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3 years ago

Solve for x please help me

Mathematics

1 answer:

hjlf3 years ago

4 0

Answer:

It's C.

Step-by-step explanation:

12x+4+9x+8=180

Combine like terms 21x+12=180

Subtract 12 from both sides 21x=168

Divide each side by 21 21x/21=168/21

x=8

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Use the figure below to answer the questions.

Archy [21]

Answer:

a. What is the name of the 3D shape?

The name of the 3D shape is Prism

b. What is the formula for total surface area for this shape?

Total surface area:

$S=2A_{b}+P_{b}h$

c. What is the surface area of the figure?

The surface area of the figure is 144 cm²

Step-by-step explanation:

a. What is the name of the 3D shape?

The 3D shape has two congruent and parallel faces (triangles) and the other faces are parallelograms, then the 3D shape is a prism

b. What is the formula for total surface area for this shape?

Total Surface area:

$S=2A_{b}+P_{b}h$

where:

Area of the base of the prism: Ab

Perimeter of the base: Pb

Height of the prism: h

c. What is the surface area of the figure?

The base of the prism is a triangle. Then to calculate the area of the base, we must use the formula to calculate the area of a triangle:

$A_{b}=\frac{bh}{2}\\ A_{b}=\frac{(4 cm)(3 cm)}{2}\\ A_{b}=\frac{12cm^{2} }{2}\\ A_{b}=6cm^{2}$

The perimeter of the base is the perimeter of the triangle, equal to the sum of the sides of the triangle:

$P_{b}=4cm+3cm+5cm\\ P_{b}=12cm$

h: Height of the prism is the distance between the bases of the prism (the triangle), then h=11 cm

Then, replacing in the formula the known values:

$S=2(6 cm^{2})+(12 cm)(11 cm)\\ S=12 cm^{2}+132 cm^{2}\\ S=144 cm^{2}$

8 0

3 years ago

What is the solution to sqrt 17-x=x+3? Show your work.

snow_lady [41]

Answer:

$x=1$

Step-by-step explanation:

Remember:

$(\sqrt[n]{a})^n=a\\\\(a+b)=a^2+2ab+b^2$

Given the equation $\sqrt{17-x}=x+3$ , you need to solve for the variable "x" to find its value.

You need to square both sides of the equation:

$(\sqrt{17-x})^2=(x+3)^2$

$17-x=(x+3)^2$

Simplifying, you get:

$17-x=x^2+2(x)(3)+3^2\\\\17-x=x^2+6x+9\\\\x^2+6x+9+x-17=0\\\\x^2+7x-8=0$

Factor the quadratic equation. Find two numbers whose sum be 7 and whose product be -8. These are: -1 and 8:

$(x-1)(x+8)=0$

Then:

$x_1=1\\x_2=-8$

Let's check if the first solution is correct:

$\sqrt{17-(1)}=(1)+3$

$4=4$ (It checks)

Let's check if the second solution is correct:

$\sqrt{17-(-8)}=(-8)+3$

$5\neq-5$ (It does not checks)

Therefore, the solution is:

$x=1$

3 0

3 years ago

I don't understand ....the teacher gave us this question with a diagram ... if you get it correctly I will mark you as the brain

Georgia [21]

Answer:

I think the answer is a I think

4 0

3 years ago

Standard deviation of 300, 785, 670, 187, 760, 724

White raven [17]

STEP 1

Mean = $\frac{300+785+670+187+760+724}{6} = \frac{3426}{6}=571$

STEP 2

Subtract the mean from each data value then square the answer
$300-571=-271$ ⇒ $(-271)^{2} =73441$
$785-571=214$ ⇒ $(214)^{2}=45796$
$670-571=99$ ⇒ $(99)^{2}=9801$
$187-571=-384$ ⇒ $(-384)^{2} =147456$
$760-571=189$ ⇒ $189^{2}=35721$
$724-571=153$ ⇒ $153^{2} =23409$

STEP 3

Add the squared answers in STEP 2 then find the mean

$\frac{73441+45796+9801+147456+35721+23409}{6}= \frac{335624}{6}=55937.3$

STEP 4

Square root the answer in STEP 3
$\sqrt{55937.3} =236.5$

Standard deviation is 236.5

7 0

3 years ago

A bag contains 4 red marbles, 3 green marbles, and 2 yellow marbles. The probability of randomly picking a yellow marble is . Wh

djverab [1.8K]

You would add the red marbles and green marbles together and which would be 7 the get the total marbles would be 9 so the answer would be 7/9 or 78%

8 0

3 years ago