Answer:
10
Step-by-step explanation:
The similarity of triangles says that the ratio between the corresponding sides is the same.
See that, if 9/6 = 1.5
So
15 / x = 1.5
We solve the equation
we multiply 15/x by x to remove the fraction
(15 / x) x = 1.5 * x
It result
15 = 1.5x
Now, we divide everything by 1.5 to leave the X alone
15 / 1.5 = (1.5x)/1.5
It result
15/1.5 = x
10 = x
