x+y=5
8.5x+10.25y=46
solve for y in the equation x+y=5 to plug into the equation 8.5x+10.25y=46 to find x:
x+y=5 --> y=-x+5
plug -x+5 in for y in the 2nd equation:
8.5x+10.25(-x+5)=46 (distribute 10.25)
8.5x-10.25x+51.25=46 (collect like terms and solve for x)
-1.75x+51.25=46
-1.75x=-5.25
x=3
Now plug 3 in for any of the x's to find x, I'm doing the 1st equations cause it's easier:
(3)+y=5
3+y=5
y=2
y=2 and x=3
(3,2)
