Answer:he invested $12000 in bonds and $8000 in stocks.
Explanation:
Let x represent the amount that was invested in the bond that made 4% profit.
Let y represent the amount that was invested in the stock that made 8% profit.
Francis invested $20,000. Some was invested in bonds that made a 4% profit, and the rest was put into stocks that made an 8% profit. This means that
x + y = 20000
Profit made from the amount invested in the bond is
4/100 × x = 0.04x
Profit made from the amount invested in stock is
8/100 × y = 0.08y
if his total profit on both types of investments was $1,120, it means that
0.04x + 0.08y = 1120 - - - - - - - - - - 1
Substituting x = 20000 - y, it becomes
0.04(20000 - y) + 0.08y = 1120
800 - 0.04y + 0.08y = 1120
- 0.04y + 0.08y = 1120 - 800
0.04y = 320
y = 320/0.04 = 8000
x = 20000 - y = 20000 - 8000
x = $12000