Question

susie buys 3 pieces of pizza and 2 cookies for a total of 6.50. the next day she buys 1 piece of pizza and 1 cookie for 2.50. how much does a cookie cost

Answer 1

1.00

Explanation:

You want to know the price of a cookie when 3 pizza slices and 2 cookies cost 6.50, while 1 pizza slice and 1 cookie costs 2.50.

Elimination

We can write equations for the costs as ...

3p +2c = 6.50

p + c = 2.50

Multiplying the second equation by 3 and subtracting the first equation eliminates the variable p.

3(p +c) -(3p +2c) = 3(2.50) -(6.50)

3p +3c -3p -2c = 7.50 -6.50 . . . . . . . eliminate parentheses

c = 1.00 . . . . . . . . . simplify

The cost of a cookie is 1.00.