Step 1, make sure you have the linear equation in the form y=mx+b.
Step 2, you can take b number and graph it on the y-axis.
Step 3, convert m into a fraction so that you have your rise over run.
Step 4, continue your line as far as you need to answer the problem.
Example: y=1/4x +5
The 5 is the number you will graph on your y-axis.
1/4 is where you will start on the 5 and go up (rise) 1 line to 6 and then go right (run) over 4 lines and place your 2nd point.
Hope this helps!