Melissa spent $41 total at the mall. she bought 6 books for $6 each, and spent the rest of her money on lunch. how much did she spend on lunch?

Melissa spent $5 on lunch.

Step-by-step explanation:

6*6=36 (price of all 6 books)

x+36=41

$5

answer: c

substitute in the values.

for a:

f(0) = 0 + 9

f(0) = 9

a is a solution.

for b:

f(7) = 14 + 9

f(7) = 23

b is a solution.

for c:

f (3) = 6 + 9

f(3) = 15

c is not a solution. it's supposed to be 14.

for d:

f(2) = 4 + 9

f(2)= 13

d is a solution.

so mark-up is 0.4 multiplied by 180 = 72