Answer:
x = 10
Explanation:
Because the triangles are similar, the following equations must be solved in order to find out how much bigger or smaller the triangle is.
10 * y = 15
16 * y = 24
You'll find that
y = 1.5
Then, you are able to insert y into the following equation and solve for x
(x - 4) * y = 9
(x - 4) * 1.5 = 9
1.5x - 6 = 9
1.5x = 15
x = 10
We can plug x back into the previous equation in order to check if it is correct
(x - 4) * 1.5 = 9
(10 - 4) * 1.5 = 9
6 * 1.5 = 9
9 = 9