Question

Dado que x+1/x=4 obtenha o valor numérico de x elevado ao cubo + 1/x elevado ao cubo???

Answer 1

x+1/x=4
x+1=4x
1=4x-x
1=3x
x=1/3

x³+1/x³=(1/3)³+1/(1/3)³=1/27+1/1/27=1/27+27=1+729/27=730/27