If x+1/x=7 , then x³+1/(x²) is equal to:

SSC CHSL 2021 PYQ — Question 58

If $x+\frac{1}{x}=7$ , then $x^3+\frac{1}{x^2}$ is equal to:

Show answer & explanation

Correct answer: D

Explanation

The correct answer is option 4 i.e. 322

If $x+\frac{1}{x}=7$

Cube on both sides

$x^3+\frac{1}{x^2}$ = 7³ - 3 *7 = 343 - 21 = 322