Answer:

Step-by-step explanation:
By definition, similar polygons have corresponding sides in a constant proportion. Therefore, we can set up the following proportion (ratio of corresponding sides) to solve for
:

I’m pretty sure it’s -15 but don’t take my word for it
<span>(3/4)*x-6 = 15 // - 15
(3/4)*x-15-6 = 0
3/4*x-21 = 0 // + 21
3/4*x = 21 // : 3/4
x = 21/3/4
x = 28</span>