Use substitution
3x = 2(-6x + 18) + 14
3x = -12x + 36 + 14
3x = -12x + 50
15x = 50, x = 50/15 = 10/3
Solution: x = 10/3
<h3>
Answer: shaded region has area 107 square feet</h3>
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Work Shown:
A = area of larger rectangle
A = length*width = 9*15 = 135 square feet
B = area of smaller rectangle
B = length*width = 7*4 = 28 square feet
C = area of shaded region
C = difference in areas of A and B
C = A - B = 135 - 28 = 107 square feet