There is an error in the work shown below. Explain the error and provide a correct solution. X cubed=125 cubed root of x cubed= cubed root of 125 x=5 and x=-5

Respuesta :

Answer:

x= 5 is the ONLY solution for the given expression and x≠ (-5)

Step-by-step explanation:

The given expression can be written as the following

[tex]x^{3}  = {125}  \sqrt[3]{x^{3} }  = \sqrt[3]{125}[/tex]

which implies x = 5 and x = -5

Now, here the given is [tex]x^{3}  = 125[/tex]

and we need to find the value of x.

So, we cube root both the sides.

We get, [tex]\sqrt[3]{x^{3} }  = \sqrt[3]{125 }[/tex]

now, 125 = 5 x 5 x 5 = [tex](5)^{3}[/tex]

So, given expression becomes  [tex]\sqrt[3]{x^{3} }  = \sqrt[3]{(5)^{3}}[/tex]

or, on simplifying, we get

[tex]x^ {3 \times {\frac{1}{3} }} = 5^ {3 \times {\frac{1}{3} }}[/tex]

or, x = 5

hence, x= 5 is the ONLY solution for the given expression.

Because if x = -5 then [tex]x^{3}  = (- 5) \times (-5) \times (-5) = -125 \neq  125[/tex]