Answer:
$17,321.43
Step-by-step explanation:
The amount of monthly income from commissions would have to be ...
$2100 -975 = $1125
This is 7% of sales over $1250, so the sales (s) would need to be ...
1125 = 0.07(s -1250)
1125 = .07s -87.50 . . eliminate parentheses
1212.50 = 0.07s . . . . add 87.50
17,321.43 = s . . . . . . . divide by 0.07
He would have to sell $17,321.43 in a month if he needed an income of $2100.