Answer:
Wish I could help try the tutor or brainy scanner.
Answer:

Step-by-step explanation:
we know that
The area of the figure is equal to the area of rectangle (figure 1) plus the area of trapezoid (figure 2)
see the attached figure to better understand the problem
The area of the rectangle is

The area of the trapezoid is
](https://tex.z-dn.net/?f=A%3D%5Cfrac%7B1%7D%7B2%7D%5B%2815-9%29%2B3%29%5D%288-3%29)
=22.5\ cm^{2}](https://tex.z-dn.net/?f=A%3D%5Cfrac%7B1%7D%7B2%7D%5B6%2B3%29%5D%285%29%3D22.5%5C%20cm%5E%7B2%7D)
The area of the figure is

It's -18.
-1/6b=3
Multiply the reciprocal of -1/6 to both sides, this will get x by itself
(-6/1)*-1/6b=3*(-6/1)
b= -18/1
b= -18
Suppose the length is 7x, the width is then 3x
7x*3x=525
21x²=525
x²=25
x=5
so the length is 7*5=35, and the width is 3*5=15