1. Which trinomial is a perfect square trinomial?

a2 – 8a + 16

a2 – 8a + 64

a2 – 4a + 16

a2 – 4a + 64

2. Which binomials are a difference of squares?

Choose exactly two correct answers.

g4 – 9

16q2 – 1

x2 + 16

m5 – 9

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.