Find the equation (in terms of x) of the line through the points (-4,3) and (2,-9).

Answer 1

Line equation has this form: y=mx+b, where m is the slope and it can be found by m=(y2-y1)/(x2-x1)

m=(3-(-9))/(-4-2)=12/-6=-2, now using a general coordinate point x,y:

-2=(y-3)/(x-(-4))

-2(x+4)=y-3

-2x-8=y-3

-2x-5=y

Answer 2

line through (-4,3) and (2,-9) has slope = (3+9)/(-4-2) = -2

is f(x) = y = minus 2x + y intercept

y = -2x + b, plug in either point to find b

3 = 8 +b, b= -5

y = -2x -5