5x + 3 = 7x – 1


what is x

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

Answer:

47/73

Step-by-step explanation:

There are 73 people who like tea. 47 are women, 26 are men. This means that the probabili that the person chosen is a women is 47 out of the 73.

Answer: 5.25 miles

Step-by-step explanation:

Answer:

Step-by-step explanation:

The words "two iles a month" tells us that the expression represened by those words is the "2x" part of the equation. x represents the number of months. The .5 part tells us that he began this process with a half mile.

Answer & Step-by-step explanation:

We use decimals every day while dealing with money, weight, length etc. Decimal numbers are used in situations where more precision is required than the whole numbers can provide. For example, when we calculate our weight on the weighing machine, we do not always find the weight equal to a whole number on the scale.

Answer:

x = -6

Step-by-step explanation:

-4x - 3(2x + 8) = 36

-4x - 6x - 24 = 36

-10x = 60

-x = 6

x = -6

Answer:

[tex]x = - 6[/tex]

Step-by-step explanation:

[tex] - 4x - 3(2x + 8) = 36 \\ - 4x - 6x - 24 = 36 \\ - 10x = 36 + 24 \\ - 10x = 60 \\ \frac{ - 10x}{ - 1 0} = \frac{60}{ - 10} \\ x = - 6[/tex]

hope this helps

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Answer:

245/999

Step-by-step explanation:

0.245bar = n

1000 n - n = 245

999n = 245

n = 245/999

Answer:

The correct option is;

105 band members

Step-by-step explanation:

The 5 values are

Minimum value = 80

Q₁ = 90

Q₂ = 105

Q₃ = 115

Maximum value = 130

Whereby the horizontal axis indicates the number of band members is a school, while the 5 values of the box plot are the percentiles of the schools in Orange County and also that the lines are graduated in increments of 5, we have that the median = 105 which is the 50% mark, therefore;

50% of high schools in Orange County have more than 105 band members.

Answer:

The answer would be 105

Step-by-step explanation:

I got this right on Khan Academy <33

Answer:

8a^3.

Step-by-step explanation:

(a+b)^3=a^3+b^3+3a^2b+3ab^2

(a-b)^3=a^3-b^3-3a^2b+3ab^2

(a+b)^3+(a-b)^3=2a^3+6ab^2

According to the question

(a+b)^3+(a-b)^3+6a(a^2-b^2)

Put in the value

=2a^3+6ab^2 +6a^3–6ab^2

=8a^3

In the simplest form expression (a + b)³ + (a - b)³ + 6a(a² - b²) can be written as,  8a³

Algebraic identities are algebraic equations that are true regardless of the value of each variable. Additionally, they are employed in the factorization of polynomials. Algebraic identities are employed in this manner for the computation of algebraic expressions and the solution of various polynomials.

Given that,

A algebraic identity,

(a + b)³ + (a - b)³ + 6a(a² - b²)

It is known that,

(a + b)³  = a³ + b³ + 3ab(a + b)

(a - b)³  =  a³ - b³ - 3ab(a - b)

So, now we can substitute expressions

(a + b)³ + (a - b)³ + 6a(a² - b²)

a³ + b³ + 3ab(a + b) + a³ - b³ - 3ab(a - b) +  6a(a² - b²)

a³ + b³ +  3a²b + 3ab² + a³ - b³ -3a²b + 3ab² + 6a³ - 6ab²

8a³

Hence, the simplest form is 8a³

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Answer: ŷ = 0.07X + 5.2

Step-by-step explanation:

Given the following :

Number of citations 5 - 7.5 - 10 - 15 - 20

Outputs Residuals 3 - - 6 - - 10 - 5 - - 6

Using the online regression calculator :

Line of best fit is represented by the equation:

ŷ = 0.06897X + 5.2069

ŷ = 0.07X + 5.2

From the line equation:

y = mx + c

With 0.07 = slope of gradient(m)

Intercept (c) = 5.2 (point where the line of best fit intersect the y_axis

x and y are values of x and y respectively

Answer:

21.66666667

Step-by-step explanation:

3x-4(0)=65

3x=65

x=21.66666667

You replace y wil 0 when you are sovling for x

Answer:

First system: no solution

Second system: one solution

Third system: one solution

Fourth system: infinite solutions

Fifth system: no solution

Step-by-step explanation:

First system: 3x-2y=3; 6x-4y=1

From the first equation: y = (3x - 3)/2

Using this value of y in the second equation:

6x - 6x + 6 = 1

6 = 1 -> System has no solution

Second system: 3x-5y=8; 5x-3y=2

From the first equation: x = (8 + 5y)/3

Using this value of x in the second equation:

5*(8 + 5y) - 9y = 6

40 + 25y - 9y = 6

16y = -34 -> y = -2.125

x = (8 - 5*2.125)/3 = -0.875

This system has one solution

Third system: 3x-2y=8; 4x-3y=1

 From the first equation: x = (8 + 2y)/3

Using this value of x in the second equation:

4*(8 + 2y) - 9y = 3

32 + 8y - 9y = 6

y = 26

x = (8 + 2*26)/3 = 20

This system has one solution

Fourth system: 3x-6y=3; 2x-4y=2

  From the first equation: x = 1 + 2y

Using this value of x in the second equation:

2*(1 + 2y) - 4y = 2

2 + 4y - 4y = 2

2 = 2

This system has infinite solutions

Fifth system: 3x-4y=2; 6x-8y=1

  From the first equation: x = (2 + 4y)/3

Using this value of x in the second equation:

2*(2 + 4y) - 8y = 1

4 + 8y - 8y = 2

4 = 2

This system has no solution

Answer:

Step-by-step explanation:

Answer:

44 cm

Please see the attached picture for full solution

Hope it helps....

Good luck on your assignment

Answer:

2

Step-by-step explanation:

x^0+ y^0

Let x = 3 and y = 2

3^0 + 2^0

Raised to the 0 power is 1

1 + 1

2

Answer:

the answer is 1, this is correct

Step-by-step explanation:

Answer:

Step-by-step explanation:

Without the variable x, your "f(x) = 3(18)*" is not a function.  If you meant

f(x) = 3(18)^x, then the domain is "the set of all real numbers," and the range is (0, infinity).

the initial value is 3:  f(0) = 3(18)^0 = 3(1) = 3

The solution is: statements accurately describe the function f(x) = 3(18)* are:

The domain is all real numbers.

The initial value is 3.

Function, in mathematics, an expression, rule, or law that defines a relationship between one variable (the independent variable) and another variable.

Without the variable x, your "f(x) = 3(18)*" is not a function.

If you meant

f(x) = 3(18)^x,

then the domain is "the set of all real numbers,"

and the range is (0, infinity).

the initial value is 3:  

f(0) = 3(18)^0 = 3(1) = 3

Hence, The solution is: statements accurately describe the function f(x) = 3(18)* are:

The domain is all real numbers.

The initial value is 3.

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Answer:

1/2

Step-by-step explanation:

Since there are a total of 14 t shirts and 7 of them were green, the experimental probability that the next one is also green is 7/14=1/2. Hope this  helps!

*diagram of floor plan is attached below

Answer:

30m²

Step-by-step Explanation:

From the floor plan shown in the attached diagram, the hall way and the living room both takes the shape of a rectangle.

To find the total area of floor to be covered, we can use the formula of the area of a rectangle to find the area of the hall way + the area of the living room.

Area of rectangle = L*B

For the hall way, L = 3.2m, B = 1.5m

Area of hall way = 3.2*1.5 = 4.8m²

For the living room, L = 6m, B = 4.2m

Area of Living room = 6*4.2 = 25.2m²

Therefore, area of floor to be covered = 4.8m² + 25.2m² = 30m²

Answer:

30m²

Step-by-step explanation:

Answer:

slope = [tex]\frac{1}{4}[/tex]

Step-by-step explanation:

Calculate the slope m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (- 2, 3) and (x₂, y₂ ) = (2, 4)

m = [tex]\frac{4-3}{2+2}[/tex] = [tex]\frac{1}{4}[/tex]

Answer: If the function is: f(x) = (x^2−3x−10)/(x−5) The function has no holes.

If the function is f(x) = x^2−3x−10/x−5 then the hole is at x = 0 (the left side goes up, and the right side goes down, as the numerator is a negative number)

Step-by-step explanation:

I am not shure of what is the function, as you used no parentheses in it, so i will solve it for two different functions:

We have the function:

f(x) = (x^2−3x−10)/(x−5)

We want to find the "hole", this means that we want to find the value of x where the denominator is equal to zero.

If you look at the function, is easy to think that in x = 5 the denominator will be equal to zero, but we need to prove it.

First, we need to see if the numerator part is also zero when x = 5.

so

5^2 - 3*x - 10 = 25 -15 - 10 = 0

Ok, let's find the other root of the quadratic function:

x^2 - 3*x - 10 = (x - 5)*(x - b) = x^2 - (b + 5)*x + (b*5)

then we have: (b + 5) = 3 and b*5 = -10

then b = -2, this means that we can write the numerator part as:

x^2 - 3*x - 10 = (x - 5)*(x + 2)

then our function is:

f(x) =   (x - 5)*(x + 2)/(x - 5) = x + 2

This function has no holes.

Now, if the function actually is:

f(x) = x^2−3x−10/x−5

Then we have an x on the denominator of the third term of the equation, this denominator is 0 only when x = 0

Answer:

x =2                x = -4

Step-by-step explanation:

-5|x + 1|+ 3 = -12

Subtract 3 from each side

-5|x + 1|+ 3-3 = -12 -3

-5|x + 1| = -15

Divide each side by -5

-5/-5|x + 1| = -15/-5

|x + 1| = 3

Since this is an absolute value, we have two solutions one positive and one negative

x+1 = 3     x+1 = -3

Subtract 1 from each side

x+1-1 = 3-1     x+1-1 = -3-1

x =2                x = -4

Answer:

the answer is c

Step-by-step explanation:

Answer:

C. x < 10

Step-by-step explanation:

2x - 8 < 12

Add 8 to both sides

2x < 20

Divide both sides by 2

x < 10

Answer:

Option C

Step-by-step explanation:

We are given the inequality 2x - 8 < 12,

[tex]2x - 8 < 12,\\2x < 20,\\x < 10\\\\Conclusion - Option C[/tex]

As you can tell, for the first step we added 8 on either side of the inequality sign, resulting with the cancelation of 8, and the addition of 8 and 20. Dividing 2 on either side of this simplified inequality, we resulted in x < 10. Note that if we were to divide by a negative value, this less than sign would be taken as a greater than sign ( same rule applies for the multiplication of a negative number ).

Solution ⇒ Option C

Answer:

See explanation

Step-by-step explanation:

[tex]9x(-2y+5x)-4xy(6x-3y)[/tex]

By the distributive property this is equal to:

[tex]9x(-2y)+9x(5x)-4xy(6x)-4xy(-3y)=\\\\-18xy+45x^2-24x^2y+12xy^2[/tex]

Hope this helps!

Step-by-step explanation:

Surface area of a cylinder:

A = (2 x pi x r x h) + (2 x pi x r^2)

(2 x pi x 5 x 25) + (2 x pi x 5^2)

785.3981 + 157.0796 = 942.4777cm^2

Volume of cylinder:

V = pi x r^2 x h

pi x 5^2 x 25 = 1963.4954cm^3

Answer:

0.62

Complete question:

What is the probability that at Aya will be offered a coupon on at least one of the days she visits the website?

Step-by-step explanation:

assuming,

A: Aya gets a coupon one day. P(A) = 0.15

B: Aya doesn't get a coupon one day. P(B) = 1 - 0.15 = 0.85

Aya doesn't get a coupon in any of 6 days  = P(B)^6 = 0.85^6 = 0.38

The probability of Aya getting at least 1 coupon after 6 days is the complement of don't getting any coupon after 6 days, that is:

1 - P(B)^6=  1 - 0.38 = 0.62

Answer:

y = - 4(x + 3)² + 7

Step-by-step explanation:

The equation of a parabola in vertex form is

y = a(x - h)² + k

where (h, k) are the coordinates of the vertex and a is a multiplier

From the graph (h, k ) = (- 3, 7 ), thus

y = a(x + 3)² + 7

To find a we require a point on the graph other than the vertex

Using (- 2, 3) , substitute into the equation

3 = a(- 2 + 3)² + 7

3 = a + 7 ( subtract 7 from both sides )

a = - 4

Thus

y = - 4(x + 3)² + 7 ← in vertex form