Question

solve quesrion number 18

Answer 1

x^2+1/x^2=66

x^2+1/x^2+2*x*1/x=66

x^2-1/x^2+2=66

x^2-1/x^2=64

x-1/x=8

x^3-1/x*3=(x-1/x)(x^2+1/x^2+x*1/x)

             =(8)(64+1)

              =73