Start with the point-slope form, which you should memorize:



Plug in 
1 for x1,
-8 for y1, and
 for .



Simplify the -(-8) as +8 on the left:



Multiply both sides by 5 to clear the fraction on the right.



Distribute the 5 on the left, cancel the 5's on the right:





Next distribute the 2 on the right:



Add -40 to both sides:



Combine terms:



Divide every number (just the numbers) by 5



Cancel the 5's on the left.  They don't cancel on the right
so just leave them as they are.





Edwin