Question 591051
Mona invests $300 at 4% yearly interest. How much does she have to invest at 9% so that the total yearly interest from the two investments exceeds $48? 
--------
Interest1: 300*0.04 = 12
--
Equation:
0.09x + 12 > 48
0.09x > 36
x > $400
===============
Cheers,
Stan H.