Answer:
? = x = 12
Explanation:
Remark
This is a proportion question. A proportion is 2 equal ratios. The two triangles are similar, which means that a proportion can be set up.
Givens
? = x
x + 8
9
9 + 6
Equation
x/(x + 8) = 9 / (9 + 6) Combine
Solution
x/(x + 8) = 9/15 Cross multiply
15x = 9(x + 8) Remove the brackets
15x = 9x + 72 Subtract 9x from both sides
15x - 9x = 72 Combine
6x = 72 Divide both sides by 6
6x/6 = 72/6
x = 12
Answer x = 12