Answer:
3x + 0.5y = 35
x + y >/= 15
Possible solution: (11, 4)
11 cupcakes, 4 cookies
____________
Cupcakes = x
Cookies = y
Cupcakes are $3 each —> 3x
Cookies are $0.50 each —> 0.5y
$35 to spend: less than or equal to =
3x + 0.5y = 35
Minimum of 15: greater than or equal to >/= 15
x + y >/= 15
____________
3x + 0.5y = 35
x + y >/= 15
Solve second for y:
y >/= 15 - x
Substitute into first:
3x + 0.5(15 - x) = 35
3x + 7.5 - 0.5x = 35
Combine like terms
2.5x + 7.5 = 35
Subtract 7.5
2.5x = 27.5
Divide by 2.5
x is less than or equal to 11
So y is less than or equal to 4
Check:
4 + 11 = 15 :)
3*11 + 0.5*4 = 35
33 + 2 = 35
35 = 35 :)