HELP ME WITH #23 PLEASE! ILL GIVE U BRAINLIEST AND ITS WORTH SOME POINTS thanks

Answer:
y=-x+6 is okay.
below it y=20-x
y-7x=6 -> y=7x+6
y+7x=8 -> y= -7x+8
3x+4y=12 -> y= -3x/4 + 12
6x+2y=6 -> y= -3x+3
Slope intercept is y=mx+b, Y can never be negative and it always will end up by itself.