Really easy but pls help

Write an inequality for this description. - one fourth of the opposite of the difference of five and a number is less than twenty.

How can you find the mean absolute deviation (mad) for this set of data?

The function y= x - 4x+ 5 approximates the height, y, of a bird, and its horizontal distance, x, as it flies from one fence post to another. all distances are in feet. complete the square to find and interpret the extreme value (vertex). select two answers: one extreme value and one interpretation.