given the points (x1,y1) and (x2,y2)
the slope is (y2-y1)/(x2-x1)
given
(1,3) and (0,-1)
slope=(-1-3)/(0-1)=-4/-1=4
slope=4
find theyint
y=mx+b
m=slope
b=yint
then x=0, the y value is the yint
(0,-1)
yint is -1
slope is 4
yint is -1
y=4x-1
f(x)=4x-1
g(x)=4x+3
g(x) has greater y int (3>-1)