Urgent these are just 3 easy fill in the blank math problems.
1. when adding *blank* signs in addition you should add and keep the sign
2. when subtracting integers you can change the minus to a plus and take the *blank* of the next number. then follow addition integer rules.
3. when adding *blank* signs in addition you should subtract and keep the sign of the larger number.

Which is the completely factored from of xy^3-x^3y

Cor d? ? me ? max recorded the heights of 500 male humans. he found that the heights were normally distributed around a mean of 177 centimeters. which statements about max’s data must be true? a) the median of max’s data is 250 b) more than half of the data points max recorded were 177 centimeters. c) a data point chosen at random is as likely to be above the mean as it is to be below the mean. d) every height within three standard deviations of the mean is equally likely to be chosen if a data point is selected at random.

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.