Question

Daca x-1/x=3 atunci x^2+1/x^2=?


(1/x = 1 supra x , x^2= x la a doua)

Answer 1

(x-1)/x=3
x-1=3x
x-3x=1
-2x=1                             ori -1
x=-1/2
(x²+1)/x²=[(-1/2)²+1)]/(-1/2)²=(1/4+1)/1/4=[(1+4)/4];1/4=5/4x4/1=5