Explanation:
Parallel lines always have equal slopes, but different y intercepts.
Line K has a slope of 5, which means line L also has this slope too. Refer to the y = mx+b form.
Plug in the coordinates of (-2,-7) as well as the slope mentioned and solve for b.
y = mx+b
-7 = 5(-2) + b
-7 = -10+b
-7+10 = b
3 = b
b = 3
The y = mx+b updates to the final answer of y = 5x+3