Down below. Please Answer, I Need Help.

Question

Angeline earns $58.50 selling lemonade over the weekend. She sold  small cups for $1.50 each and  large cups for $3.00 each. She sold a total of 27 cups. How many small and large cups of lemonade did she sell?

Answer 1

1.5S + 3C = 58.50

S+ C = 27 multiply by 1.5

1.5S + 1.5C = 40.5 subtract from 1st equation

1.5C = 18

C=18/1.5 = 12 large cups

S=27-12 = 15 small cups