x = 20 - -5 = 20 + 5 = 25
y = 16 - 1 = 15
Equation
A = (b1 + b2)*h /2
Givens
b1 = 5 feet
b2 = 7 feet
h = 3 feet
Sub and solve
Area = (5 + 7)*3/2
Area = 12*3/2
Area = 36/2
Area = 18 Square feet.
16% discount, this is because 213.36-254 over the original price (254) times 100% equals -16%
