Question

if x^2 +1/x^2=27 then x-1/x=?

Answer 1

(a-b)^2=x^2+1/x^2-2×1=27-2=25
x -1/x=+5
is your answer

Answer 2

(x-1/x)² = x²+1/x²-2x 1/x

(x-1/x)²= 27-2

(x-1/x)² = 25

x-1/x = √25

x-1/x = ±5


Hope it helps u:-)