Ronelio invests $29,000 in two one-year certificates of deposit. One certificate pays 4%, and the other pays 4.75% simple interest annually.

(a) Construct a model for the total interest I(x) Ronelio earns in one year on his investments. (Let x represent the amount invested at 4%.)

(b) If Ronelio's total interest is $1332.50, how much money did he invest in each certificate?

1 answer

(a)

i(x) = .04 x + .0475 (29,000 - x)

= 1377.50 - .0075 x

(b)

1332.50 = 1377.50 - .0075 x