Helpo please

x = - 1 is extraneous

Step-by-step explanation:

= x ( square both sides )

4x + 5 = x² ( subtract 4x + 5 from both sides )

0 = x² - 4x - 5 ← in standard form

0 = (x - 5)(x + 1) = 0 ← in factored form

Equate each factor to zero and solve for x

x - 5 = 0 ⇒ x = 5

x + 1 = 0 ⇒ x = - 1

As a check

Substitute these values into the equation and if both sides are equal then they are solutions.

x = 5

left side = = = = 5

right side = x = 5

Then x = 5 is a solution of the equation

x = - 1

left side = = = = 1

right side = x = - 1

Then x = - 1 is an extraneous 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:

answer: d. $20

step-by-step explanation:

just took the test