Respuesta :

Answer:

x=18

Step-by-step explanation:

We need to find the areas of the rectangles

1st rectangle

A= l*w

A = (2x+4)*9

   = 18x+36



2nd rectangle

A = l*w

   = 15*(3x-30)

    = 45x-450


Since the area of the rectangles are equal, we set these two equations equal

18x+36 = 45x-450

Subtract 18x from each side

18x-18x+36 = 45x-18x-450

36 = 27x-450

Add 450 to each side

36+450 =27x

486 = 27x

Divide by 27 on each side

486/27 = 27x/27

18=x