Chapter 8 - Section 8.4 - Equations Quadratic in Form - Exercise Set - Page 635: 8

{$4$}

Since, $u^2+u-6=0$ Factorize the expression as follows: $(u+3)(u-2)=0$ or, $u=${$-3,2$} Replace $u$ with $\sqrt x$, we have $\sqrt x=-3$ which has no solution. or, $\sqrt x=2 \implies x=2^2$ and $x=4$ Hence, our solution set is $x=${$4$}