Question 274733
3x+y=20 
y=-3x+20 (red line).
2x+2y=24
2y=-2x+24
y=-2x/2+24/2
y=-x+12 (green line).
Line intercepts (4,8)
{{{ graph( 300, 200, -6, 15, -10, 20, -3x +20, -x +12) }}} (graph 300x200 pixels, x from -6 to 15, y from -10 to 20, of TWO functions -3x +20 and -x +12).