Answer:
$ 50,000 stocks, $ 85,000 bonds and $ 20,000 CDs.
Step-by-step explanation:
We have a system of 3x3 equations, which would be as follows:
Be it "s" stocks, "b" bonds and "c" CDs, we have to:
s + b + C = 155000
0.079 * s + 0.04 * b + 0.0375 * C = 8100
0 * s + b - C = 65000
When introducing this, in a solved of any matrices on the internet it gives us the following results:
C = 20000
b = 85000
s = 50000
In other words, it invested $ 50,000 stocks, $ 85,000 bonds and $ 20,000 CDs.