Question

if x+1/x=5 find the value of x3+1/x3

Answer 1

Answer:

X=5

X+1=5+1=6

X3+1/X3

=12+1/15

13/15

Answer 2

x+1/x=5

cubing both sides

(x+1/x)³=125

x³+1/x³+3(x+1/x)=125

x³+1/x³+15=125

x³+1/x³=110