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.
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.