Is (5, 20) a solution of the equation y = 4x explain. A. Yes, 5 = 5. B. No, 5 ≠ 4.
C. Yes, 20 = 20 D. No, 5 ≠ 80.

C. yes, 20 = 20

Step-by-step explanation:

the equation is y=4x and from the coordinates (5,20) we can see that x =5 and y = 20

substituting in the original equation we must check if

20 = 4(5)

20 = 20

left = right

yes it is a solution

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:

i think it would be 42cm