Chapter 8 - Section 8.4 - Equations Quadratic in Form - Exercise Set - Page 636: 29

{$1$}

Since, $2u^2-u-1=0$ Factorize the expression as follows: $(2u+1)(u-1)=0$ or, $u=${$-\dfrac{1}{2},1$} Replace $u$ with $x^{1/4}$, we have $x^{1/4}=-\dfrac{1}{2}$ ; which has no solution and $x^{1/4}=1\implies x=1^4$ $x=1$ Hence, our solution set is $x=${$1$}