In the third degree polynomial function f(x) =x^3 + 4x, why are 2i and -2i zeros?

For each proportion find the unknown number x 1/5/8=×/15

Suppose that one doll house uses the 1 inch scale, meaning that 1 inch on the doll house corresponds to 1/2 foot for life-sized objects. if the doll house is 108 inches wide, what is the width of the full-sized house that it's modeled after? in inches and feet.

Hannah paid $3.20 for 16 ounces of potato chips. hank paid $3.23 for 17 ounces of potato chips. who paid less per ounces?