Linear equations

Question

Maricopa's Success scholarship fund receives a gift of $ 170000. The money is invested in stocks, bonds, and CDs. CDs pay 6 % interest, bonds pay 4.3% interest, and stocks pay 6.9% interest. Maricopa Success invests $ 45000 more in bonds than in CDs. If the annual income from the investments is $ 9685 , how much was invested in each account?

Answer 1

Let K = $1000

B= bonds

C= CDs

S= stocks

B=45K + C

6C + 4.3B + 6.9S = 968.5K

C+B + S = 170K

S=170K-B-C = 170K-45K-C-C = 125K-2C

6C + 4.3(45K+C) + 6.9(125K-2C) = 968.5K

6C + 4.3C -13.8C =(968.5-193.5-862.5)K = -87,5K

-3.5C = - 87.5K

C = 87.5/3.5 = $25,000

B = $70,000

S=170-25-70 = $75,000