algebra
posted by bobby .
a painter charged $320 to paint two walls that measure 12 feet by 9ft and two walls that measured 10 ft by 9 ft. The client asks him to return to paint two walls that measue 15 ft by 12 ft and two walls that measure 18.5 feet by 12 ft. If the painter charges the same rate, what shoud the price be

2*12*9 + 2*10*9 = 396 ft^2
2*15*12 + 2*18.5*12 = 804 ft^2
so, charge
804/396 * $320 = $649.70