Hey there! I'm happy to help.
Let's think of the line segment KM as a road. It starts at point K and ends at M. You start driving from point K and after 4 miles, you have reached point L. The segment KL is equal to 4 because the distance between K and L is 4.
From point L to point M, you drive 11 miles. You are now at the end of the road. We want to find out how long the road is.
From point K to point L, you drove for 4 miles.
Then, from L to M, you drove 11.
We combine these...
11+4=15
The length of KM is 15.
Have a wonderful day! :D
The answer is D. He divided both sides by 5 instead of dividing both sides by -5.
RULE : ASA i.e angle- side-angle
Hope it helps you....