All of the following expressions have the same value, when x = -2 and y = 4, except . x 2y
(-2) 2y
-4x 2
-2xy

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

What properties allow transformation to be used as a problem solving tool

Assume that the weights of quarters are normally distributed with a mean of 5.67 g and a standard deviation 0.070 g. a vending machine will only accept coins weighing between 5.48 g and 5.82 g. what percentage of legal quarters will be rejected? round your answer to two decimal places.