Answer:
$4000 was invested into 3% interest and $7000 was invested into 4% interest.
Step-by-step explanation:
let n be amount invested into fund1 at 3%
let p be amount invested into fund2 at 4%
n + p = 11,000 <=equation for initial investments
0.03n + 0.04p = 400 <=equation for interest earned
Rearrange n+p=11,000.
n = 11000 - p Substitute this equation into the other for "n"
0.03n + 0.04p = 400
0.03(11000 -p) + 0.04p = 400
330 - 0.03p + 0.04p = 400
330 + 0.01p = 400
0.01p = 70
p = 7000
Substitute p=7000 into an equation to find n
n + p = 11000
7000 + n = 11000
n = 4000
