Math word problem i cant figure out

Question

I ordered 5 burgers and 2 fries for 17.75

I then ordered 2 bugers and 3 fries for 10.25

What does a burger cost

What does a fry cost

Answer 1

This is an exercise in solving 2 equations with 2 unknowns

Let b = number of burgers and f= number of fries

5b + 2f = 17.75

2b +3f. =10.25

I will multiply the top equation by 3 and the bottom one by 2 so I can get the coefficient of f to be equal in both

15b + 6f = 53.25

4b + 6f = 20.50. Subtract equation 2 from equation 1 leaves you

11b = 32.75 b=2.98

substitute 2.98 for b in the original equation to solve for f = 1.43