Question

pls help... urgent ​

Answer 1

Answer:

18

Step-by-step explanation:

x8 + 1/x8 = 47

(x4)2 + (1/x4)2 = 47

(x4+1/x4)^2 - 2*x4*1/x4 = 47

(x4+1/x4)^2 -2 = 47

(x4+1/x4)^2 = 49

x4+1/x4 = 7 (taking positive value only)

(x2+1/x2)^2 - 2*x2*1/x2 = 7

(x2+1/x2)^2 - 2 = 7

(x2+1/x2)^2 = 9

x2+1/x2 = 3 (taking positive value only)

now

X6+1/X6 = (x2)3 + (1/x2)3

= (x2+1/x2)^3 - 3*x2*(1/x2)*(x2+1/x2)

= 3^3 - 3*3

= 27-9

= 18