Answer
$y-5=3(x-1)$
Work Step by Step
Recall:
The equation of a line whose slope is $m$ and passes through the point $(x_1, y_1)$ is:
$$y-y_1=m(x-x_1)$$
Thus, the equation of the line whose slope is $3$ and passes through the point$(1, 5)$ is:
$$y-5=3(x-1)$$