Show all work to factor x4-5x2+4

x = 1 or -1  

x = -2 or 2

Step-by-step explanation:

x4 - 5x2 + 4 = 0

x4 - 4 x2 - x2 + 4 =0

x2 ( x2 - 4 ) - 1 ( x2 - 4 ) = 0

( x2 - 1 ) ( x2 - 4 ) =

x2 - 1 = 0         or          x2 - 4 = 0

x2 = 1                            x2 = 4

x = 1 or -1                              x = -2 or 2

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places