math
posted by danica on .
the dimensions of a door are 3ft by 7ft 6in. if the same amount is added to each dimension of the door, the area is increased by 18ft^2. Find the dimensions of the new door.

(3+x)(7.5+x) = 3*7.5+18
x = 3/2
new dimensions: 4'6" by 9'0"
check:
3*7.5 = 22.5
4.5*9 = 40.5