At a snack stand,Nathan buys 2 sodas and 1 snack and spends 5 dollars. Olivia buys 3 sofas and 4 snacks and spends 15 dollars.
how much does a soda cost?
How much does a snack cost?
So you are given this:
2s + 1 c = 5 c = snack....as in candy bar
3s + 4c = 15 multiply top equation by -4 to get:
-8s - 4c = -20 now add the two bottom equations.... the 'c' will be gone and you can solve for 's'
then use this value of 's' in one of the equations to solve for 'c'