Y= 150
Start by using substitution.
Change x+y=375 to x=375-y
Substitute this into 1.25x+0.75y=393.75
1.25(375-y)+0.75y=393.75
Distribute the 1.25
468.75-1.25y+0.75=393.75
Add like terms (y)
468.75-0.5y=393.75
Subtract 468.75 to the right
-0.5y=-75
Divide by -0.5
y=150
