The slope intercept form of a line can be written as:
[tex]y=mx+b[/tex]where m is the slope and b is the y-intercept.
We have two points of the line: (-1,1) and (0,3).
Knowing that for x=0, the value of y=3 tells us that the y-intercept b is b=3:
[tex]\begin{gathered} y=mx+b \\ 3=m\cdot0+b \\ 3=b \end{gathered}[/tex]Using the other point and replacing the values of x and y in the equation we can calculate the value of the slope m:
[tex]\begin{gathered} y=mx+3 \\ 1=m\cdot(-1)+3 \\ 1-3=-m \\ -2=-m \\ m=2 \end{gathered}[/tex]Then, with m=2 and b=3, the equation becomes:
[tex]y=2x+3[/tex]Answer: y=2x+3