So 1 hour= 60 minutes
60+25= 85 minutes
Now we should subtract the 42
85-42=43
Answer: Choice B) 
We have some value m and we're squaring it to get 
To undo this and isolate m, we apply the square root to both sides

There are two solutions here. This is similar to how there are two solutions in something like
(those two solutions being x = 5 and x = -5). Squaring any negative number leads to a positive result because
negative times negative = positive.
The answer is 31
29 - 13 is 16
16 + 15 is 31