15b^2+20y^3
Find the greatest common factor

Twice the sum of a number and 4 is equal to three times the difference of the number and 7. find the number.

Find the values of y: 3y^3(y^2+ 2/3y)=0

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?