find the equation of the line
slope=(y2-y1)/(x2-x1)
slope=(6-2)/(7-(-3))=4/10=2/5
slope is 2/5
y=mx+b
y=2/5x+b find b
input a point
6=2/5(7)+b
6=14/5+b
minus 14/5 from both sides
3 and 1/5=b
16/5=b
xintercept is when y=0
0=2/5x+16/5
minus 16/5 from both sides
-16/5=2/5x
times both sides by 5/2 to clear fraction
-8=x
xintercept is -8 or (-8,0)
