Hey guyss i need with 3 of these questions : )
i'm supposed to express these with positive exponents
1. 2a^-4/5b^-2
2. (5a^3n)^3
3. (x^n+5/y)^2

2people are trying different phones to see which one has the better talk time. chatlong has an average of 18 hours with a standard deviation of 2 hours and talk-a-lot has an average of 20 hours with a standard deviation of 3. the two people who tested their phones both got 20 hours of use on their phones. for the z-scores i got 1 for the chatlong company and 0 for talk-a-lot. what is the percentile for each z-score?

What statement is true? 2x^2-9x+2=-1

Astraight water slide is 175 feet above ground and is 200 feet long. what is the angle of depression to the bottom of the slide?