We shall begin by identifying two points on the line of the equation and these are;
[tex]\begin{gathered} A(0,-4),B(1,-1) \\ \text{The slope m, is derived as follows} \\ m=\frac{y_2-y_1}{x_2-x_1} \\ (x_1,y_1)=(0,-4) \\ (x_2,y_2)=(1,-1) \\ m=\frac{-1-\lbrack-4\rbrack}{1-0} \\ m=\frac{-1+4}{1} \\ m=3 \\ \text{The value of b in the equation} \\ y=mx+b \\ \text{can now be derived as follows;} \\ -4=3(0)+b \\ -4=0+b \\ b=-4 \\ (\text{Note that we have substituted for the values of x, y and m)} \\ y=mx+b\text{ is now derived as;} \\ y=3x+\lbrack-4\rbrack \\ y=3x-4 \end{gathered}[/tex]
