7TH GRADE MATH. PLS HELP

Answer:

31

Step-by-step explanation:

To rationalise 7 + 3[tex]\sqrt{2}[/tex] , multiply by its conjugate

The conjugate of 7 + 3[tex]\sqrt{2}[/tex] is 7 - 3[tex]\sqrt{2}[/tex] , then

(7 + 3[tex]\sqrt{2}[/tex])(7 - 3[tex]\sqrt{2}[/tex]) ← expand using FOIL

= 49 - 21[tex]\sqrt{2}[/tex] - 21[tex]\sqrt{2}[/tex] - (3[tex]\sqrt{2}[/tex])²

= 49 - 18

= 31

Answer:

C

Step-by-step explanation:

==========================================================

Explanation:

"Use 3 for pi" is something I've never seen a teacher do before. Usually it's "use 3.14 for pi".

Anyway, the diameter of this cylinder is 2 inches, which cuts in half to 1 inch. This is the radius.

The height is 10 inches.

So we have r = 1 and h = 10

V = pi*r^2*h

V = 3*1^2*10

V = 30 cubic inches approximately

Answer:

V = 30

Step-by-step explanation:

1. lets find the radius

r = 1/2 diameter

2/2 = 1

r = 1

2. plug in our info into the equation!!!- using 3 for pi as said in the question

V = (pi) r^2 h

V = (3)*(1)^2*(10)

3. solve

V = 30

Answer:

3*6 × 3*-3 × 3*6

3*(6-3+6)

3*9

Answer:

SOLUTION: " The largest US standard postage stamp ever issued has a width of about 1 inch, which was 3/4 of the height of the stamp. Write and solve an equation to find the height of the st

Answer:

33

Step-by-step explanation:

Pamela-x

Jiri-x+14

x+x+14=52

2x=52-14

2x=38

x=19-Pamela

19+14=33-Jiri

check: 19+33=52

Answer: Jiri is 33 years old, and Pam is 19.

Step-by-step explanation:

Let's put Jiri as x, and Pam as y. We know that Pam's and Jiri's age =52. Pam is 14 years younger than Jiri(x)

You can model the situation by two equations:

y=x-14

x+y=52

Substitute y into second equation

x+x-14=52

2x=66

x=33

Jiri is 33

and back to the first equation

y=33-14=19, Pamela's age.

Answer:

1. Given

2. Vertical angle theorem

3. AB≅DB, EB≅CB, m<ABC≅m<DBE

4. △ABC ≅ △DBE

Hope this helps :D

Answer:

y = 4

Step-by-step explanation:

From the question given above, the following data were obtained:

Angle θ = 45

Hypothenus = 4√2

Adjacent = y =?

The value of y can be obtained by using cosine ratio as illustrated below:

Cos θ = Adjacent / Hypothenus

Cos 45 = y / 4√2

Cross multiply

y = 4√2 × Cos 45

Recall

Cos 45 = 1 / √2

Therefore,

y = 4√2 × 1/√2

y = 4

Answer:

m<XUY = 40

Step-by-step explanation:

The central angles theorem states that in a circle, the measure of an angle with its vertex on the center of the circle is equal to the angle measure of the arc surrounding it. As a given fact, the sum of degree measures in a circle is (360) degrees. Thus, one can form the following equation:

(mZUV) + (mVUW) +(mWUX) +(mXUY) + (mYUZ) = 360

Substitute,

(-15x) + (30) + (90) + (x + 47) + (95) = 360

Simplify,

(-15x) + (30) + (90) + (x + 47) + (95) = 360

-14x + 262 = 360

Inverse operations,

-14x + 262 = 360

-14x = 98

x = -7

Substitute back into the equation for the measure of angle (<XUY)

m<XUY = x + 47

= -7 + 47

= 40

Answer:

x=-6

Step-by-step explanation:

-1/2(6x+10)=13

Distribute

-3x -5 = 13

Add 5 to each side

-3x-5+5 = 13+5

-3x = 18

Divide by -3

-3x/-3 = 18/-3

x=-6

Answer:

plotting the (x,y) coordinates in graph

Answer:

(x + y - 2xy)*(x + y + 2xy)

Step-by-step explanation:

x^2-4x^2y^2+y^2+2*x*y

=x^2 + 2xy + y^2 - (2xy)^2

=(x + y)^2 - (2xy)^2

=(x + y - 2xy)*(x + y + 2xy)

Answer:

x = (b-c)/a

Step-by-step explanation:

ax + b = c

Subtract b from each side

ax+b-b = c-b

ax = b-c

Divide by a

ax/a = (b-c)/a

x = (b-c)/a

Answer:

x= (C-B)A

Step-by-step explanation:

Answer:

(i) 7/10

(ii) 3/10

(iii) 1/5

(iv) Rs 40,000

Step-by-step explanation:

The fraction of the salary spent on food = 1/2

The fraction of the salary spent on rented house fee = 1/5

(i) The fraction spent for both food and rental fee = (1/2) + (1/5) = (5 + 2)/10 = 7/10

(ii) The remainder (rest) of the salary = 1 - 7/10 = 3/10

The fraction of the remainder spent for children's education = 1/3

The fraction of the total salary spent for the children's education = (1/3) × (3/10) = 1/10

(iii) The remaining portion deposited in the bank = 1 - (1/10 + 7/10)) = 2/10 = 1/5

(iv) The amount equal to portion of 1/5 of his salary deposited in the bank is Rs 8000

Let x represent his whole salary, we have;

(1/5) × x = Rs 8,000

x = 5 × Rs 8,000 = Rs 40,000

His whole salary is Rs 40,000.

Answer:

Degree: 2

Polynomial type: Quadratic

Step-by-step explanation:

One is asked to identify the degree and type of polynomial when given the following expression:

[tex]-10k^2+7[/tex]

The degree of a polynomial refers to the exponent to which it is raised. In essence, the largest exponent in the expression. In this case, the largest exponent in this polynomial is (2). An expression to the second degree is referred to as a quadratic expression.

Answer:

Step-by-step explanation:

r = 12 cm

Theta = 62

Length of arc = [tex]\frac{theta}{360}*(2\pi r)[/tex]

                      [tex]=\frac{62}{360}*2*3.14*12[/tex]

                      = 12.98 cm

Answer:

3.88

Step-by-step explanation:

1. Subtract 5.74 from both sides of the equation

9.62-5.74=3.88

[tex]we conclude that option B:[/tex]

[tex]y + 5 = -\frac{1}{2}*(x - 3)^2[/tex]

[tex]Is the graphed function.[/tex]

On the graph we can see a parabola that opens downwards, so it has a negative leading coefficient.

We also can see that the vertex of the parabola is on the point (3, -5)

Then the equation of the parabola is something like:

y + 5 = a*(x - 3)^2

Where a is a negative real number.

The only option of this form is option B, so we conclude that option B:

[tex]y + 5 = -\frac{1}{2}*(x - 3)^2[/tex]

Is the graphed function.

If you want to learn more about parabolas:

https://brainly.com/question/4061870

#SPJ1

Answer:

9.89949 or 9.9

Step-by-step explanation:

7^2 + 7^2 = c^2

49+49=98

square root of 98 = 9.89949

The correct statement is test is reliable and authentic as the probability of no false positives is more than 0.5

Given that

[tex]H_o:P= 0.50\\\\H_1:P>0.50[/tex]

Now following calculations to be done to reach the conclusion:

There is no false positive as

= 100 - 5.5

= 94.5%

[tex]\hat P =0.945, n = 12[/tex]

Now

[tex]z = \frac{\hat P - P}{\sqrt\frac{P(1-P)}{n} }\\\\=\frac{0.945-0.5}{\sqrt\frac{0.5\times0.5}{12} } \\\\= 3.08[/tex]

So

P value = P(z >3.08) = 0.0010

Therefore we can conclude that test is reliable and authentic as the probability of no false positives is more than 0.5

Learn more about the polygraph test here:

brainly.com/question/3790493

Answer:

-10ab

STEP BY STEP EXPLANATION

2a (3a + b) -3a(2a +4b)

6a² + 2ab - 6a²- 12ab

2ab-12ab 6a²-6a²

-10ab

Hope this will help you if not then sorry :)

Answer:

[tex]2a( 3a + b)- 3a(2a+4b)[/tex]

Expand by distributing terms.

[tex]6a ^{2} +2ab-3a(2a+4b)[/tex]

Expand by distributing terms.

[tex]6a 2+2ab-(6a^{2} +12ab)[/tex]

Remove parentheses

.[tex]6a ^{2} +2ab-6a^{2} -12ab[/tex]

Collect like terms.

[tex](6a^{2}-6a^{2})+(2ab-12ab)[/tex]

[tex]=-10ab[/tex]

OAmalOHopeO

Answer:

The sum of interior angle is 360°

Answer:

30/360 ×π r^2 = AB

AB = 30 /360 × π ×6^2

AB = 9.42 IN

Answer:

40.2

Step-by-step explanation:

Circumference = 2πr

Plug in:

2π6.4

6.4 × 2 = 12.8

π = 3.14

12.8 × 3.14 = 40.1920.... = 40.2

The answer is 40.2

Hope this helped.

Answer:

Your answer should be 20.1

Step-by-step explanation:

6.4 x 3.14= 20.096

Rounded to the nearest tenth is 20.1

hope this helps c:

Answer:

200

hope it help

Answer:

160

Step-by-step explanation:

got it right

Answer:

C i think sorry if its wrong

Step-by-step explanation:

Answer:

bottom left one

note the >, < ≤ , ≥

for x > 0 the dot should NOT be solid

Step-by-step explanation:

Answer:

B. 4

Step-by-step explanation:

54 - 4 = 50

50 - 4 = 46

46 - 4 = 42

42 - 4 = 38

Answer: D. -4

Step-by-step explanation: took the quiz and got it right.

Answer:

b) y

Step-by-step explanation:

joannes speed = 250/2.5 =100km/h

francois speed = 100-10 = 90km/h

after 5h, francois would have travelled 450