7z + 10 - z = 8z - 2(z - 5)
7z + 10 - z = 8z - 2z + 10
6z + 10 = 6z + 10
6z - 6z = 10 - 10
0 = 0
Therefore, 7z + 10 - z = 8z - 2(z - 5)
We will have to use proportions:

Cross multiplying we get

Now divide:

Solve to tenths place we get

The woman casts a 36.6 ft long shadow.
Area of the figure
= (area of rectangle) + (area of triangle)
= (8 × 10) + (½ × 4 × 8)
= 80 + 16
= 96
Area = 96ft²
Quarts of paint needed
= 96/22
= 48/11
= 4.36
Mr. Chen will have to buy 5 quarts of paint.