Question 734854
Let x = cost of hot dog, y = cost of hamburger,

we have

5x + 2y = 10.25  and

2x + 5y = 12.50

we need to know the value for x

solve the second equation for y and we have

y = (12.50 - 2x) / 5 = 2.50 - 2x/5

now we substitute for y in our first equation,

5x + 2 (2.50 - 2x/5) = 10.25  combining like terms,

5x + 5.00 - 4x/5 = 10.25 and

5x - 4x/5 = 5.25 and

25x - 4x = 26.25  and 21x = 26.25

x = $1.25, so the hot dog costs $1.25