What is the sign of -4ab−4abminus, 4, a, b when a>0a>0a, is greater than, 0 and b<0b<0b, is less than, 0?

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?