If he sells his property for $59,139.78 and pays 7% commission, this will allow him to retain a net of $55,000
Here's how i figured it out:
x = sale price
(sale price) - (sale price * 7%) = net price of $55,000
(x) - (0.07x) = 55,000
x(1 - 0.07) = 55,000
x = (55,000)/(1 - 0.07) = (55,000)/(0.93) = 59,139.78
x = $59,139.78