Return rate, r = 3% = 0.03
x = initial investment
b = final balance
After 1 year, the balance i
b = initial investment + interest
b = x + r*x = (1 + r)*x
Because r = 0.03,
b = 1.03x (after 1 year)
Move the 8 over
-x=3x-8
Move the 3x over
-x-3x=8
-4x=8
Divide by -4
x=-2
