84.15-1.8*8
Order of Operations says to add and subtract before you multiply, so simplify the expression to: 82.35*8, which is 658.8
The patch doubles in size each day so, on the 47th will be half the size than on the 48th day
(fg)(x) = [f(x)][g(x)]
(fg)(x) = (4x - 5)(3) = 12x - 15
