Question 148

If $$x + \frac{1}{x} = 7$$, then $$x^3 + \frac{1}{x^3}$$ is equal to:

Solution

We have $$x+\frac{1}{x}=7$$
Taking cubes on both sides we get :
$$x^3+\frac{1}{x^3}+3\left(x+\frac{1}{x}\right)=343$$
we get $$x^3+\frac{1}{x^3}=343-21=322$$

Share on Whatsapp Share on Whatsapp

Create a FREE account and get:

Free SSC Study Material - 18000 Questions
230+ SSC previous papers with solutions PDF
100+ SSC Online Tests for Free

SSC CPO 13th-March-2019-Shift-2

If $$x + \frac{1}{x} = 7$$, then $$x^3 + \frac{1}{x^3}$$ is equal to:

Free SSC Quant Questions

Login to your Cracku account

Hello! 👋

Ready to Unlock Your Success?

Please Enter Your OTP

Please enter the following details

Create a free Cracku account