2+1=3 is not an identity property. The rest are because the value equals itself after dividing, subtracting, and multiplying.
Answer:
y=2x+2
Step-by-step explanation:
Remember that parallel lines have equal slopes. We can solve this using point slope form which is 
Plug in the point (0,2) into the equation:
y-2=m(x-0)
Also plug in the slope which is the same as line EF (m=2)
y-2=2(x-0)
Simplify:
y-2=2x
Add 2 to both sides:
y=2x+2
'x' was calculated correct.
y = 180° - 78° = <u>102</u><u>°</u>