She invested x dollars at 2% and 4x dollars at 3%. Write the total annual interest equation 0.02x + 0.03*(4x) = 1120 dollars. Simplify and find x 0.02x + 0.12x = 1120 0.14x = 1120 x = 1120/0.14 = 8000. ANSWER. $8000 invested at 2% and $32000 invested at 3%