math
posted by Marie P. .
Ronelio invests $29,000 in two oneyear 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?

(a)
i(x) = .04 x + .0475 (29,000  x)
= 1377.50  .0075 x
(b)
1332.50 = 1377.50  .0075 x