MUST FIND THE AMOUNT INVESTED IN EACH DIFFERENT THING

Question

ountry Day's scholarship fund receives a gift of $ 120000. The money is invested in stocks, bonds, and CDs. CDs pay 2.75 % interest, bonds pay 2.1 % interest, and stocks pay 7.5 % interest. Country day invests $ 35000 more in bonds than in CDs. If the annual income from the investments is $ 5587.5 , how much was invested in each vehicle? 

Answer 1

.0275c + .021b + .075s = 5587.5

b = 35000+c

c + b + s = 120,000

3 equations 3 unknowns

solve by substitution elimination or matrix algebra

.075s = 5587.5 - .0275c - .021(35000+c)

s = (5587.5 -.0275c - .021(35000+c))/.075

simplify, solve for stock investment

then for cds and bonds

check the answer, as the calculations get tedious