Answer
{$81$}
Work Step by Step
Since, $2u^2-5u-3=0$
Factorize the expression as follows: $(2u+1)(u-3)=0$
or, $u=${$-\dfrac{1}{2},3$}
Replace $u$ with $x^{1/4}$, we have
$x^{1/4}=-\dfrac{1}{2}$ ; which has no solution
and $x^{1/4}=3\implies x=3^4$
$x=81$
Hence, our solution set is $x=${$81$}
