Question

20. (4) Given, ( frac{x+frac{1}{x}}{x-frac{1}{x}}=frac{5}{4} )
( Rightarrow quad 4 timesleft(x+frac{1}{x}right)=5left(x-frac{1}{x}right) )
( Rightarrow quad 4 x+frac{4}{x}=5 x-frac{5}{x} )
( Rightarrow quad 5 x-4 x=frac{4}{x}+frac{5}{x} Rightarrow x=frac{9}{x} Rightarrow x^{2}=9 )
( therefore quad x=pm sqrt{9}=pm 3 )

# 20. 1(x+ D):(*- _)=5:4, then the value of x is (1) 0 (2) 1 (3) 2 (4) 3

Solution