Respuesta :

irspow
y=5-3x   add 3x to both sides

3x+y=5

...

x=2y-3  subtract 2y from both sides

x-2y=-3   (by convention x should have a positive coefficient)
1. Subtract the y on both sides and get 0=5-3x-y
Then subtract the on both sides and get the answer
-3x-y=-5

2. Substructure 2y on both sides and get the answer
x-2y=-3