If a and bare real numbers, which equation represents the Commutative Property of Multiplication?

(a) compute the maclaurin polynomial m2(x) for f(x) = cos x. (b) use the polynomial of part (a) to estimate cos π 12. (c) use a calculator to compute the error made using the estimate from part (b) for the value of cos π 12. remember that the error is defined to be the absolute value of the difference between the true value and the estimate.

What is the value of x in the following equation. -x ^3/2 = -27

How do i simply this expression (quadratic formula basis) on a ti-84 or normal calculator?