-3 • (5x + 2y = 7)
-15x - 6y = -21
-2x + 6y = 9
__________
-17x = -12
x = 12/17
5(12/17) + 2y = 7
2y = 7 - 60/17
2y = 3.47
y = 1.735
Let the width be w, then length = 2w - 1
Area = length times width = w(2w - 1) = 21.
Thus, 2w^2 - w = 21 or 2w^2 - w - 21 = 0
Solving the quadratic equation gives that w = 3.5.
Therefore, width is 3.5 ft and length is 2(3.5) - 1 = 6 ft.
Go 2 openstudy hope that helped
