Equation of line y = mx+ c

m is the gradient, a measure of steepness for the line

m = Change in y

      Change in x

m =   -2-(-5)

        -4-(-1)

note how the numbers in brackets are in the same position

m = -2+5 =   3   = -1

       -4+1     -3

You need to use the m value, by substation to find the value of c.

m = -1 (-4, -2) x = -4, y = -2
-2 = -1(-4) + c
-2 = 4 + c
-6 = c

The equation is y = -x - 6

Note we do not write -1x this is, by convention, written as -x.