If you know the slope and one point (x,y) of a linear equation to find the y-intercept you use the next equation (general equation for a linea):
[tex]y=mx+b[/tex]b is the y-intercept
Then, you use the value of the slope (m) and the value of the point (x,y) and substitute those values in the equation above to find b.
Example:
If the slope is 4
Point (4, 5)
[tex]\begin{gathered} 5=4\cdot4+b \\ 5=16+b \\ 5-16=b \\ -11=b \end{gathered}[/tex]y intercept for the example is -11
