Acorner store sells two kinds of baked goods: cakes and pies. a cake costs $5 and a pie costs $7. in one day, the store sold 15 baked goods for a total of $91. how many cakes did they sell?
-i know the answer is 7, but how do you solve it? what's the work?
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7 cakes and 8 pies

Step-by-step explanation:

To solve, write two equations: one for the total number and the other for the total sales.

Let c be the number of cakes.

Let p be the number of pies.

So c + p =15, the total sold.

And 5c + 7p = 91 for the total $ sales.

Solve by substitute one equation into another.

c + p = 15 becomes c = 15 - p. Substitute it into 5c + 7p = 91.

5(15-p) + 7p = 91

75 - 5p + 7p = 91

75 + 2p = 91

2p = 16

p=8

To find c, substitute p=8 into c = 15 - p.

c = 15 - 8

c = 7

the number of the people going.

step-by-step explanation:

the cost to buy one movie ticket is $7. if the total cost for the movie is a function of how many people go, then the input is : the number of the people going.