Factoring trinomials

can you me understand this a little more the question is this

13y squared - 5yx - 8x squared

Find the difference (8ab+a+2) - (3ab+6)

Afootball quarterback has two more chances to throw a touchdown before his team is forced to punt the ball. he misses the receiver on the first throw 25% of the time. when his first throw is incomplete, he misses the receiver on the second throw 15% of the time. what is the probability of not throwing the ball to a receiver on either throw?

What is 60.9643790503 to 5 decimal