<span>Simplifying
3x + -1y = 12
Solving
3x + -1y = 12
Solving for variable 'x'.
Move all terms containing x to the left, all other terms to the right.
Add 'y' to each side of the equation.
3x + -1y + y = 12 + y
Combine like terms: -1y + y = 0
3x + 0 = 12 + y
3x = 12 + y
Divide each side by '3'.
x = 4 + 0.3333333333y
Simplifying
x = 4 + 0.3333333333y</span>
P = 2(L + W)
P = 28
L = 2W - 1
28 = 2(2W - 1 + W)
28 = 2(3W - 1)
28 = 6W - 2
28 + 2 = 6W
30 = 6W
30/6 = W
5 = W ....width is 5 ft
L = 2W - 1
L = 2(5) - 1
L = 10 - 1
L = 9 <=== length is 9 ft
The answer is C, 6 x 4 = 24!