12x-5y=20 y=x+4

3x+y=3 x=-y+3

Standard form (which I assume is what they want you to turn these into) is y=mx+b.

12x-5y=20 is y=2.4x-4.

Subtract 12x from both sides, - 5y=-12x+20.

Multiply both sides by - 1, 5y=12x-20.

Divide both sides by 5, y=2.4x-4.

y=x+4 is already in standard form - I'm not quite sure what to do.

3x+y=3 is y=-3x+3.

Subtract 3x from both sides, y=-3x+3.

x=-y+3 is y=-x+3

Ad y to both sides, y+x=3.

Subtract x from both sides, y=-x+3.