X + 3 • ( 10 + y ) - 7x - 4
x + 30 + 3y - 7x - y
x - 7x + 3y - y + 30
-6x + 2y + 30
112 dallors interest beca0.02x + 0.04(800) = 112 0.02x + 0.04(x + 800) = 112 0.04x + 0.02(x + 800) = 112 use
If you take 3.5 and divide it by 0.05, or times 20, that would make it 70.
