Answer:the number of cupcakes that Sue purchased is 12
Step-by-step explanation:
Let x represent the number of cupcakes that Sue purchased at the bakery.
Let y represent the number of cookies that Sue purchased at the bakery.
She needs to serve 36 people. This means she would purchase a total of 36 people. Therefore,
x + y = 36
Cupcakes cost $2.50 each, cookies cost $1.00 each. She spends $54.00. This means that
2.5x + y = 54 - - - - - - - - - 1
Substituting x = 36 - y into equation 1, it becomes
2.5(36 - y) + y = 54
90 - 2.5y + y = 54
- 2.5y + y = 54 - 90
- 1.5y = - 36
y = - 36/ - 1.5
y = =24
x = 36 - y = 36 - 24 = 12
