Do my homework i'm failing geometry and i don't know how to do this i'm desperate

Which functions are even? check all of the boxes that apply. f(x) = x4 – x? f(x) = x2 – 3x + 2 f(x) = (x - 2) f(x) = x done

What is the area of a pizza with a radius of 40 cm leave the answer in terms of π to find your exact answer 40π cm² 1600π cm² 800π cm² 80π cm² π=pi

How do you find principle and simple interest