Katy invests a total of $26,500 in two accounts paying 4% and 9% annual interest, respectively. how much was invested in each account if, after one year, the total interest was $1,510.00.

A = amount invested at 4%.

b = amount invested at 9%.

we know the total amount invested was $26500, thus a + b = 26500.

whatever% of anything is just (whatever/100) * anything.

how much is 4% of a?  well, is just (4/100) * a, or 0.04a.

how much is 9% of b?  well, is just (9/100) * b, or 0.09b.

we know the interest yielded for both amounts adds up to $1510, thus 0.04a + 0.09b = 1510.



how much was invested at 9%?  well, b = 26500 - a.