Explanation:
given data:
gained = $1,570
amount invested = $29,000
0.11x – 0.07( $29,000 – x ) = 1540
0.11x – ( 2030 – 0.07x ) = 1540
0.11x + 0.07 = 1540 +2030
0.18x = 3570
divide both sides by 0.18
x = 19833.33 ( amount invested at 11%.
$29,000 – 19833.33
= $9166.7 ( amount invested at 7%)