Question

Solve the equation after making the appropriate substitution. Need help!

Answer 1

Answer:

Step-by-step explanation:

First realize that

$(x^{1/3})^{2}=x^{2/3}$

Usually when you are asked to solve making a substitution you need to find substitute a term leaving a quadratic equation.

if you replace:

$x^{1/3}=u$

$u^{2}-3u-18 = 0 \\(u-6)(u+3)= 0 \\u = 6 \\u = -3 \\x^{1/3} = 6 => x = 6^{3} = 216\\x^{1/3} = -3 => x = (-3)^{3} = -27$