Question

write the equation of the line through (4,-7) and (2,0)

Answer 1

y=ax+b

a=delta y / delta x = (0--7)/(2-4) = 7/-2 = -3.5
so y=-3.5x +b
we fill in one point:
0=-3.5 * 2 + b
0 = -7 + b
so b=7

y=-3.5x + 7