What is measure of angle B + Measure of angle C

D

Step-by-step explanation:

Supplementary angles sum to 180°, thus

∠ A + ∠ B = 180°, that is

30° + ∠ B = 180° ( subtract 30° from both sides )

∠ B = 150°

Complementary angles sum to 90°, thus

∠ A + ∠ C = 90°, that is

30° + ∠ C = 90° ( subtract 30° from both sides )

∠ C = 60°

Thus

∠ B + ∠ C = 150° + 60° = 210° → D

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:

step-by-step explanation: