Choose the correct simplification of the expression −3x2(5x − 4x2 − 6). a.−7x4 + 2x3 − 9x2 b.12x4 − 15x3 + 18x2 c.12x4 + 15x3 + 18x2 d.−12x4 + 15x3 − 18x2

The answer is B

Step-by-step explanation:

(−3x2)(5x−4x2−6)

=(−3x2)(5x+−4x2+−6)

=(−3x2)(5x)+(−3x2)(−4x2)+(−3x2)(−6)

=−15x3+12x4+18x2

=12x4−15x3+18x2

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation:

answer:

your answer is: c. 196 7/8 in^3.