Shelby bought 4 hamburgers and 2 orders of fries for $16.50. samuel bought 5 hamburgers and 3 orders of fries for $21.25 at the same time. how much did one hamburger cost?

Hamburgers costs $3.50 each.

x- Hamburgers

y- Fries

Shelby: 4x + 2y = $16.50

Samuel: 5x + 3y = $21.25

4x+2y=16.50

-4x       -4x

2y=-4x+16.50

Divide by 2

y = -2x+8.25

Then use substitution

5x + 3(-2x+8.25) = 21.25

5x -6x +24.75 = 21.25

x=3.50

the answer is y = 11.54

hope this : )