Um, so it's a bit awkward with this question because they actually got the x value incorrect. When they added up all the values, they got 9x - 27 = 180, but it's actually 9x + 27 = 180 because -18 + 45 is positive 27. Anyways, when you solve it correctly you get x = 17, and then you substitute it into the angles. So with 5x - 18, you are saying 5(× 17) - 18 = 67. Then with the other one you do 4(× 17) + 45 = 113. You know that x is definitely 17 because 113 + 67 = 180.

4 0

3 years ago

The length of the sides of a triangle are x, 2x+2, and 13. If the perimeter of the triangle is 30, what is the value of x?

scZoUnD [109]

Add all the sides up to equal 30 in an equation because you are given the perimeter. The perimeter is the length around a two dimensional shape. This means the perimeter is the length of all the side lengths added together.

(x) + (2x + 2) + (13) = 30

Combine like terms.

3x + 15 = 30

Subtract 15 from both sides.

3x = 15

Divide both sides by 3.

$\boxed {x = 5}$

3 0

3 years ago