Question

Y=-3x+12 Y=3x-6 How do I solve this step by step system of substitution

Answer 1

$\left \{ {{y=-3x+12} \atop {y=3x-6}} \right. \\\\ Equal\ both\ equations\\\\\ -3x+12=3x-6\ \ \ | subtract\ 3x\\\\ -6x+12=-6\ \ \ | subtract\ 12\\\\ -6x=-18\ \ \ | divide\ by\ -6\\\\ x=3\\ y=3*3-6=9-6=3$