Question

if x+1/x=7, find the value of xcube + 1/x cube .​

Answer 1

Answer:

217

Step-by-step explanation:

x+1/x=7

x+1=7x

1=7x-x

6x=1

x=1/6

x^3=(1/6)^3

=1/216

x^3+1/x^3=  (1/216 +1)/1/216

=(1+216)/216 / 1/216                        [LCM is taken between 1/216 and 1]

=217/216 *216/1 [since it is division it becomes reciprocal and in turn we should multiply]

=217