Question 1019096
Let us call what she invested at 12%, x.
The amount invested at 9% must then be $70000 - x.
The setup looks like this
.12x + .09(70000-x) = 8100
.12x + 6300 - .09x = 8100
.03x + 6300 = 8100
.03x = 1800 and
x = 1800/.03 = $60,000 invested at 12%