On graph paper, show how 10/1 and 1/10 are related

What are the possible rational zeros of [tex]f(x) = x^4+2x^3-3x^2-4x+18[/tex]

Can someone answer this question? : )

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.