A mother wants to invest $6000 for her children's education. She invests a portion of the money in a bank certificate of deposit (CD account) which earns 4% and the remainder in a savings bond that earns 7%. If the total interest earned after one year is $360, how much money was invested at each rate?

Respuesta :

0.04x+0.07(6000-x)=360
0.04x+420-0.07x=360
0.04x-0.07x=360-420
−0.03x=−60
X=60/0.03=2,000 at 4%
6000-2000=4000 at 7%