Answer
See the graph below.
Work Step by Step
If we interpret the slope, we can say that if $m=3$, then for every $1$ unit of change in $x$ (also known as the run), $y$ changes by $3$ (also known as the rise).
Using this information, we can easilty get the coordinates of a second point. plot the points, then complete the graph by connecting the two points using a straight line.
The starting point is given $(1,2)$, after that, we have to add the aforementioned changes to the $x$ and $y$-coordinates.
Next point can be:
$(1+1,2+3)=(2,5)$
By sketching these two points on the graph, we can connect them to form the line given in the exercise.