Answer: her sales for the month of May is $55000
Step-by-step explanation:
Let x represent her total sales for the month of May.
Each month she receives a 5% commission on all her sales of medical supplies up to $20,000. This means that for her first sales worth $20000, she earns a commission of
5/100 × 20000 = 1000
She also earns 8.5% on her total sales over $20,000. This means that for sales over $20000, she earns
8.5/100(x - 20000) = 0.085x - 1700
Her total commission for May was $3,975. The expression becomes
1000 + 0.085x - 1700 = 3975
0.085x = 3975 + 1700 - 1000
0.085x = 4675
x = 4675/0.085
x = 55000