Question 433583
0.09y+0.04x=1240

3x=y (this is because she has three times the amount at 9%. So 3 x the amount at 4% = the amount at 9%)
substitue this into the first equation
0.09(3x)+0.04x=1240

0.27x+0.04x=1240
0.31x=1240

x=1240/0.31
x=4000
so she has $4000 at 4% and 12000 at 9%

hope this helps