Given:
slope of 2
points (1,2) and (3,y)
Recall the slope-intercept form of the equation of a line.
[tex]\begin{gathered} y=mx+b \\ \text{where} \\ m\text{ is the slope} \\ b\text{ is the y-intercept} \end{gathered}[/tex]
Substitute the following values to the slope-intercept form
[tex]\begin{gathered} (x,y)=(1,2) \\ m=2 \\ \\ y=mx+b \\ 2=(2)(1)+b \\ 2=2+b \\ 2-2=b \\ 0=b \\ b=0 \end{gathered}[/tex]
With b = 0, m = 2, and x = 3, substitute again to the slope-intercept form
[tex]\begin{gathered} y=mx+b \\ y=(2)(3)+0 \\ y=6+0 \\ y=6 \end{gathered}[/tex]
Therefore, the value of y is equal to 6.
