Persamaan garis yang melalui titik P(2,-3) dan Q(4,-7)

y-y1/y2-y2 = x-x1/x2-x1
y+3/-7+3 = x-2/4-2
y+3/-4 = x-2/2
2(y+3) = -4(x-2)
y+3 = -4x+8 /2
y = -2x+4-3
y= -2x+1