ANSWER
y = 3x - 8
EXPLANATION
The equation of a line is:
[tex]y=mx+b[/tex]
where m is the slope and b is the y-intercept.
In this problem we know that the slope is m = 3. To find the y-intercept we have to replace x and y by the point and solve for b:
[tex]\begin{gathered} y=3x+b \\ 7=3\cdot5+b \\ 7=15+b \\ b=7-15 \\ b=-8 \end{gathered}[/tex]
Therefore, the equation is:
[tex]y=3x-8[/tex]
