Word problem pre calc

Question

Curt can be paid in one of two ways for the furniture he sells plan A: salary of $450 per month plus a commission of %10 of sales plan B: salary of $750 per month plus a commission of %15 sales in excess of $ 5000. For what amount of monthly sales is plan b better than A assuming curts sales always more than $5000? ( plan B is better than plan A when curts sales are more than what?) please give the answer to this question

Answer 1

The plans will pay the same amount when 450 +.1S= 750 + .15(S-5000)

45000 + 10S = 15S - 75000

5S= 75000+45000

S=24000

For S>24000 plan B is better