That would be the zero identity property. Hope it helps!
Since L1//L2 , angle 1 = angle 5
You are given the formula
m = (y2-y1)/(x2-x1)
You can pick any two points on table
Let’s choose (9,2) and (3,-2)
Plug in the values into formula
m = (-2-2)/(3-9)
m = -4/-6
Simplify: m = 2/3
Solution: m = 2/3
Answer D
use photomath and sub to pewdiepie