The base of a rectangle is 6 inches greater than twice the height. The perimeter is 78 inches. Find the area.
b = 2h + 6
2b = 78 - 2h
Add the two abolve equations to eliminate h.
3b = 84
b = 28
2h = b-6 = 22
h = 11
Area = b*h = 11*28 = 308 in^2