I made some brownies and cookies to sell for a local fundraiser. The cookies sold for $0.75 each and the brownies sold for $1.25 each. If I sold 51 baked goods and made $53.25 from the bake sale, which item’s sales made the most money? Cookies Brownies

Brownies made the most money

Step-by-step explanation:

Let c = cookies

b = brownies

We sold 51 items  so c+b = 51

Cookies are .75  and brownies are 1.25

.75c + 1.25 b = 53.25

We have 2 equations and 2 unknowns

c = 51-b

Substituting into the second equation

.75(51-b) + 1.25b = 53.25

Distribute

38.25-.75b +1.25b = 53.25

Combine like terms

38.25+.5b = 53.25

Subtract 38.25 from each side

38.25 +.5b -38.25 = 53.25 -38.25

.5b =15

Divide each side by .5

.5b/.5 = 15/.5

b = 30

Now find c

c =51-b

c = 51-30

c = 21

They sold 30 brownies and 21 cookies

30 brownies * 1.25 =37.50

21 cookies *.75 = 15.75

Brownies made the most money

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value