The complete question is:
A certain element has a half life of 4.5 billion years.
You find a rock containing a mixture of the element and lead. You determine that 30% of the original element remains; the other 70% decayed into lead. How old is the rock?
Answer:
Age of rock = 7.82 billion years
Step-by-step explanation:
For a first order decay, fraction remaining is given by the formula 0.5n where n = number of half lives elapsed.
We are given that;
fraction remaining = 30% = 0.3
Thus;
0.3 = 0.5n
To find n, we have to use the log function;
log 0.3 = n log 0.5
-0.5229 = -0.301 n
n = -0.5229/-0.301
n = 1.737
We are given that;
Half life = 4.5 billion years
So, 1.737 half lives would give;
1.737 × 4.5 = 7.82 billion years
So, age of rock = 7.82 billion years
plz answer as fast as possible
What is the value of 3/7 * 0.1 / 5/21?
Answer:
B
Step-by-step explanation:
3/7 * 1/10 * 21/5
=63/350
=9/50
A triangle on a coordinate plane is translated according to the rule T-8,4(x,y). Which is another way to write this rule
Answer:
(x, y) → (x + 8, y + 4)
Step-by-step explanation:
Answer: C
Step-by-step explanation
Just took the test
What is the equation of a line, in general form, that passes through point (1, -2) and has a slope of 1/3. 1.x - 3 y - 7 = 2.x - 3 y + 7 = 0 3. 3 x - y - 7 = 0
Answer:
x- 3y - 7=0
Step-by-step explanation:
the line in the slope-intercept form:
y= mx+bm= 1/3 and point given (1, -2) by using which we find y-intercept:
b= y-1/3xb= -2- 1/3*1= - 7/3y= 1/3x- 7/3General form of a line is: ax+by+c= 0
converting:
y= 1/3x- 7/3 ⇒ 3y= x- 7 ⇒ x- 3y - 7=0Answer:
x- 3y - 7=0
Step-by-step explanation:
Mark me BRAINLIEST please
Please answer !!!!!!!! Will mark brainliest !!!!!!!!!!!!
Answer:
B)
D)
Step-by-step explanation:
B) 1 and 13 are x intercepts so true
D) greatest profit is when price is 7; after that profit is getting smaller because function is decreasing
Emily and Rachel had lunch at the mall. Emily ordered two slices of pizza and three cookies and her bill was $8. Rachel ordered one slice of pizza and four cookies and her bill was $9. What was the price of one slice of pizza? What was the price of one cookie?
Answer:
one slice of pizza: $1
one cookie: $2
Step-by-step explanation:
Emily: two pizzas (1+1)+three cookies (2+2+2)= 8
Rachel: one pizza (1)+four cookies (2+2+2+2)= 9
can i plz get brainilest? :)
Answer:
piza 1 buck
cooky 2 bucks
Step-by-step explanation:
i did not look at the other answer...
lol i copied the other answer
Find the area of the figure. If needed, round to the nearest tenth.
Isosceles trapezoid
An isosceles trapezoid with bottom base length of 14 feet, top base of 7 feet, and height of 6 feet.
a.
63 sq. ft
b.
27 sq. ft
c.
49 sq. ft
d.
126 sq. ft
Answer:
a. 63 ft²
Step-by-step explanation:
A= 1/2(b1+b2)h
b1= 14 ftb2= 7 fth= 6 ftA= 1/2(14+7)*6= 63 ft²Answer:
[tex]63 {ft}^{2} [/tex]
Answer A is correct
Step-by-step explanation:
[tex]area = \frac{1}{2} (a + b)h \\ = \frac{1}{2} \times (7 + 14) \times 6 \\ = \frac{1}{2} \times 21 \times 6 \\ = \frac{126}{2} \\ = 63 {ft}^{2} [/tex]
hope this helps
Wendy and her friend Sandra went to dinner. Their total food bill was $25.00. The tax was 7%. How much was the tax? How much was the bill including the tax?
Answer:
the answer is 175
Step-by-step explanation:
you will do 2500*7/100
Please Help ASAP!
Select the situations that represent a function. (A,B,C,D)
Answer:
A and B both have an input that has multiple outputs so the answer is C and D.
In A, tangent HF and chord EG intersect to form ZHEG. Find mZHEG.
A. 118°
B. 236°
C. 242°
D. 3540
Please select the best answer from the choices provided
B
D
Answer:
A.
Step-by-step explanation:
a car is drawn with a scale of 1 in: 4 yards. find the actual length of the car if the drawing if the car has a length= 3in
Answer:
So since you have the ratio of 1 : 4
we need to find 3 : x
since 1*3 = 3. We multiply all by 3
4*3 =12.
Answer is 12
Find the slope of this graph.
Answer:
WERE THE GRAPH
Step-by-step explanation:
During the last 5 basketball games, Javier scored 13 , 20, 13, 15, and 24 points.
What is the median of the data? *
Answer:
15
Step-by-step explanation:
First you have to order the numbers from least to greatest
13, 13, 15, 20, 24
Then you find the value in the middle.
You have five numbers so your middle value is the number between the the two numbers on the left and the two numbers on the right which is 15.
A high school graduating class is made up of 351 students. There are 73 more girls than boys. How many boys are in the class?
Answer:
let x be the number of boys
given, the number of girls are 73 more than the number of boys, meaning number of girls is x + 73
also given is that x + x + 73 = 351
2x + 73 = 351
2x = 351 - 73
2x = 278
x= 139
There are 139 boys
There will be 139 + 73 = 212 girls
139 + 212 = 351 which is the total number of students
let x be the number of boys.
Given, that the number of girls is 73 more than the number of boys, meaning the number of girls is x + 73
also given is that
x + x + 73 = 351
2x + 73 = 351
2x = 351 - 73
2x = 278
x= 139
There are 139 boys
There will be 139 + 73 = 212 girls
139 + 212 = 351 which is the total number of students.
What is the term for graduating high school?To graduate means to successfully complete your schooling, to become "a graduate." When you graduate from high school, you become a high school graduate and congratulations are in order. A graduate is someone who has received a degree from a school.
Learn more about graduating high school here: https://brainly.com/question/14862649
#SPJ2
Which equation is equivalent to -2(2 − 2x) = 4 − 8(1 − x)
0 = 4x
8 = 4x
4 = -4x
16 = -4x
Answer:
8 = 4x OR 0 = 4x
Step-by-step explanation:
I not %100 sure or it could be 0 = 4x
EITHERONE
AC is included between
1
A
c
O A. ZA and ZC
O B. ZA and ZB
O C. AB and BC
O D. BC and AC
Since angle A and angle C forms side AC, AC is included between: A. ∠A and ∠C.
What is an Included Side?An included side is a side that is in between two angles in a triangle, where the rays of the angles overlap.
Thus, in triangle ABC, side AC lies in between angle A and angle C.
Therefore, since angle A and angle C forms side AC, AC is included between: A. ∠A and ∠C.
Learn more about included side on:
https://brainly.com/question/3168048
Answer: A
Step-by-step explanation:
the lines shown below parallel. if the green line has a slope of -1, what is the slope of the red line
Answer:
-1
Step-by-step explanation:
Parallel lines have the same slope
If the green line has a slope of -1, the red line has a slope of -1
sally has a part time job mowing lawns so she can save money for a new car. she charges $5 per hour define the independent and dependent variables
Answer:
Independent: Amount of hours she works
Dependent: Amount of money she makes
Step-by-step explanation:
The independent variable is the part of the equation that changes. In this case the only thing that changes is how long she works, the amount of money she charges and what she is doing does not change.
The dependent variable is what you measure in the equation. In this case, the amount of money she makes depends on the amount of time she works.
EB and DA are diameters of circle Y. What is the measure of arc EDC?
Answer:
Option (D). 110°
Step-by-step explanation:
Since EB and AD are diameter,
[tex]m(\widehat{ECB})[/tex] = [tex]m(\widehat{ACD})[/tex] = 180°
[tex]m(\widehat{ECB})=m(\widehat{EDC})+m(\widehat{BC})[/tex] = 180° -------(1)
And [tex]m(\widehat{ACD})=m(\widehat{AB})+m(\widehat{BCD})[/tex]
180° = 40° + [tex]m(\widehat{BCD})[/tex]
[tex]m(\widehat{BCD})[/tex] = 140°
Since, [tex]m(\widehat{BCD})=m(\widehat{BC})+m(\widehat{CD})[/tex]
[tex]2m(\widehat{BC})[/tex] = 140° [Given [tex]m(\widehat{BC})=m(\widehat{CD})[/tex]]
[tex]m(\widehat{BC})[/tex] = 70°
From equation (1),
[tex]m(\widehat{EDC}})[/tex] = 180° - [tex]m(\widehat{BC})[/tex]
[tex]m(\widehat{EDC}})[/tex] = 180°- 70°
Therefore, measure of arc(EDC) = 110°
Option (D) will be the answer.
HELP PLEASE !! NEED HELP ASAPPP !! Will give brainliest !!!
−→− bisects ∠DGF, m∠DGE=53∘. Find m∠DGF.
1. what is the measure of angle DBF? (image included below)
Answer:
Measure of angle DBF = 106°.
Step-by-step explanation:
Given in the question,
m∠DGE = 53°
and line segment GE is the angle bisector of ∠DGF.
Since segment GE is the angle bisector of ∠DGF that means it divides the angle DGF into two equal parts.
Therefore, m∠DGE ≅ m∠FGE
m∠DBF = m∠DGE + m∠FGE
m∠DBF = 2(m∠DGE)
= 2(53)°
= 106°
Therefore, measure of angle DBF = 106°.
Ay is any one down to work together on this? Not just this question but the whole unit of geometry
A piece of rope measuring 4m is cut into 8 equal lengths. How long will each piece be?
Answer:
each piece will be half a metre long
Step-by-step explanation:
4m into cm is 400cm
400 divided by 8 is 50cm
in metres this would be 0.5m a.k.a half a metre
1. Using the figure below, what is the measure of angle ABE?
Answer:
see below
Step-by-step explanation:
Because ∠ABE and ∠CBD are vertical angles, ∠ABE = ∠CBD = 40°.
Answer:
The angle of ∠ABE is 40°.
Step-by-step explanation:
Given that ∠ABE and ∠CBD are opposite vertical angles so they have the same measure of angles.
Which statements are true? Check all that apply. Magnitude is never a negative value. The magnitude of –1.9 is |–1.9| which is 1.9. The absolute value of a number is greater than its magnitude. The numbers –4 and 4 have the same magnitude. The magnitude of Negative two-thirds is less than the magnitude of Two-thirds.
Answer:
A, B, D
Step-by-step explanation:
The options are:
A. Magnitude is never a negative value
This is true because the magnitude is only a representation of the numerical value of a number. It is the distance of the number from the 0 point on the number line. It is the absolute value of a number.
Hence, the polarity of the number is not necessary.
B. The magnitude of –1.9 is |–1.9| which is 1.9
This is true because they have the same numerical value.
C. The absolute value of a number is greater than its magnitude
This is false because absolute value and magnitude of a number are the same.
D. The numbers –4 and 4 have the same magnitude
This is true. They have the same absolute value, hence, they have the same magnitude.
E. The magnitude of -2/3 is less than the magnitude of 2/3
This is false as already explained in C above.
Answer:
a b d
Step-by-step explanation:
1⁄7 + 1⁄2 + 3⁄4 =jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj
Answer:j=39/28 or 1.392857 or 1 11/28
Step-by-step explanation:
I assume that you are looking for j
1⁄7 + 1⁄2 + 3⁄4=j
9/14+3/4
39/28
What’s 4x^2+28x+24 factored?
Answer:
[tex](4x + 4)(x + 6) \\ [/tex]
Step-by-step explanation:
[tex]4 {x}^{2} + 28x + 24 \\ 4 {x}^{2} + 24x + 4x + 24 \\ 4x(x + 6) + 4(x + 6) \\ (4x + 4)(x + 6)[/tex]
hope this helps you.
brainliest appreciated
good luck!
have a nice day!
Carol is y years old and her daughter is 25 years younger.find carols present age if sum of ages in 6 years time is 75
ahh please help me with this question!!!!
Answer: B. 2∛3
Step-by-step explanation:
[tex]24^\frac{1}{3}[/tex] is equivalent to ∛24. This can actually be simplified. We can use prime factorization to simplify the cubed root.
24
/ \
2 12
/ \
2 6
/ \
2 3
From this prime factorization tree, we want to find a group of 3. The same number that appears 3 times.
We see that there are 3 2's. They are bolded above. Since there is a group of 3, we can pull the 2 out of the cubed root, as we are left with a 3 inside (underlined above).
Our final answer is 2∛3.
Define polynomial with some examples.
Answer:
A Polynomial can be expressed in terms that only have positive integer exponents and the operations of addition, subtraction, and multiplication. In other words, it must be possible to write the expression without division.
Step-by-step explanation:
EXAMPLES :
x2 + 2x +5 Since all of the variables have integer exponents that are positive this is a polynomial.5x +1 Since all of the variables have integer exponents that are positive this is a polynomial.(x7 + 2x4 - 5) * 3x Since all of the variables have integer exponents that are positive this is a polynomial.5x-2 +1 Not a polynomial because a term has a negative exponent3x½ +2 Not a polynomial because a term has a fraction exponent(5x +1) ÷ (3x) Not a polynomial because of the division(6x2 +3x) ÷ (3x) Is actually a polynomial because it's possible to simplify this to 3x + 1 --which of course satisfies the requirements of a polynomial. (Remember the definition states that the expression 'can' be expressed using addition,subtraction, multiplication. So, if it's possible to simplify an expression into a form that uses only those operations and whose exponents are all positive integers...then you do indeed have a polynomial equation) [Polynomial Equation- is simply a polynomial that has been set equal to]An algebraic expression is of the form of a0+a1x+a2x2+.........+anx^n,where n is positive integer and the coefficients a0,a1,A2,.......an are constants with an is not equal to 0 is called a polynomial of degree.
A polynomial in X is denoted by p(x),q(x),g(x) etc.
Examples:
p(X)=x^2-3x+2 is a polynomial in X.
Similarly,the polynomial in two variables X and y are generally denoted by p(x,y) and polynomial in three variables is denoted by p(x,y,z).
Hope it helps
Good luck on your assignment...
the base of a pyramid is equilateral triangle of side 8cm long. If the altitude of the pyramid is 15cm ,find it's volume
Answer:
V = 80√3 cm³
Step-by-step explanation:
V = Ab×h/3
Ab = l²√3/4 = 64√3/4 = 16√3 cm²
V = 16√3cm²×15cm/3
= 16√3cm²×5cm
= 80√3 cm³
Answer:
138.56cm2
Step-by-step explanation:
B.a×hx1/3
B.a=1/2×8×8sin60=27.71cm2
1/3×27.71×15=138.56cm2
Need some help with a few consecutive integer word problems, tysm if you do :)
The sum of three consecutive odd integers is -57. Find the integers.
A. -19, -17, -15
B. -19, -21, -23
C. -21, -19, -17
D. -21, -23, -25
Three times the greater of two consecutive odd integers is 5 less than 4 times the smaller. Find the integers.
A. 8, 9
B. 7, 9
C. 11, 13
D. 3, 5
Five times the smaller of two consecutive odd integers is 11 more than 4 times the greater. Find the integers.
A. 13, 15
B. -7, -5
C. -7, -9
D. 19, 21
Answer:
Answers are: A,D, and A
Step-by-step explanation:
I hope these are right
answer quick pls ill give 10
Answer:
60
Step-by-step explanation:
360-95-120-85=60
