Question

Can’t understand the
$x - 1/x = 3\\ find x^{3} - 1/x^{3}$3 ).

Answer 1

Answer:

30

Step-by-step explanation:

x-1/x=3

x³-1/x³=(x-1/x) ( x²+1/x²-x*1/x)

=3* (  x²+1/x²-2x*1/x+1*x/x)

=3*  { (x-1/x)²+1)

=3( 3²+1)

=3*(9+1)

=30