D is the correct answer I think.
For this case we must factor the following expression:

Rewriting the expression:

We factor using the formula of the square difference:

Where:

So:

From the second term we have:

Finally, the factored expression is:

Answer:

horizontal shrink by a factor of 1/2
4 units to the left
50+79=129
180-129=51
X=51
Explanations
Angles on a straight line add up to 180 degrees. So 180-101=79 degrees
50 degrees is an opposite angle so it moves into the internal angle.
Angles in a triangle add up to 180 so (180-50-79=51)
Ans is 51 I think
Answer:
5 mins
Step-by-step explanation:
680/4
=170 meters (quarter of 680m)
170/34
=5 mins