The equation of a line is written in the form,
[tex]\begin{gathered} y=mx+b \\ \text{The slope is m, and its given as 4} \\ x=1,y=-9 \\ \text{Therefore,} \\ y=mx+b\text{ becomes} \\ -9=4(1)+b \\ -9=4+b \\ \text{Collect like terms and you have} \\ -9-4=b \\ b=-13 \\ \text{Substitute the values of m and b into the equation and you'll have} \\ y=mx+b \\ y=4x+\lbrack-13\rbrack \\ y=4x-13 \end{gathered}[/tex]
The equation of the line therefore is
y = 4x - 13
