Question 167948
4,80
12,160
slope=(y2-y1)/(x2-x1)=(160-80)/(12-4)=80/8=10 ans.
Y=mX+b
80=10*4+b
80=40+b
b=80-40
b=40
Y=10x+40 is this line equation. 
{{{ graph( 300, 200, -6, 5, -10, 50, 10x +40) }}} (graph 300x200 pixels, x from -6 to 5, y from -10 to 50, 10x +40).