Tony invests $3900 in two different accounts. The first account paid 6 %, the second account paid 8 % in interest. At the end of the first year he had earned $280 in interest. How much was in each account?

amount invested at 6% ---- x

amount invested at 8% ---- 3900-x

.06x + .08(3900-x) = 280
times 100
6x + 8(3900-x) = 28000

continue