31. A 20 m deep well with radius 7m is dug and the earth from digging is evenly spread out to form a
platform 22m X 14m. Find the height of the platform.​

Height of rectangle block = 10 m

Step-by-step explanation:

Given:

Height of well = 20 m  

Radius of well = 7 m

Dimension of rectangle = 22m x 14m

Find:

Height of rectangle block

Computation:

Volume of well = Volume of rectangle block

πr²h = (l)(b)(h)

(22/7)(7)²(20) = (22)(14)(Height of rectangle block)

(22/7)(49)(20) = (308)(Height of rectangle block)

3080 = 308(Height of rectangle block)

Height of rectangle block = 10 m

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:

the answer is d

the answer is in the first quadrant, which make the y-int positive.

since the dots are going down, therefore the correlation is negative

i hope it is right.