Question

At a local coffee shop, three coffees and two muffins cost a total of $7.00. Two coffees and four

muffins cost a total of $8.00. How much would six cups of coffee and 1 muffin cost?

Answer 1

$10.25

Explanation:

Set up a system of equations, so 3c + 2m = 7 and 2c + 4m = 8, where c = the cost of coffees, and m = cost of muffins

To solve multiply the first equation by -2(3c + 2m=7) so you get -6c -4m = -14 now add the two equations

-6c - 4m = -14

2c + 4m = 8 notice that -6c + 2c = -4c and -4m + 4m cancels, then -14+8=-6

so we have -4c = -6 so c = $1.50

To solve for m, substitute c = 1.50 so 3(1.50) + 2m = 7, so solve for m so

4.5 + 2m = 7, 2m = 2.5, so m = $1.25

So now solve the final problem 6(1.50) + 1(1.25) = $10.25