Answer:
The amount invested at 7% is $1,400 and the amount invested at 9% is $7,600
Step-by-step explanation:
Let
x ----> amount invested at 7%
(9,000-x) -----> amount invested at 9%
we know that
The interest earned by the amount invested at 7% plus the interest earned by the amount invested at 9% must be equal to $782
so
The linear equation that represent this problem is
[tex]0.07(x)+0.09(9,000-x)=782[/tex]
solve for x
[tex]0.07x+810-0.09x=782\\0.09x-0.07x=810-782\\0.02x=28\\x=\$1,400[/tex]
[tex](9,000-x)=9,000-1,400=\$7,600[/tex]
therefore
The amount invested at 7% is $1,400 and the amount invested at 9% is $7,600