Check the picture below.
[tex]\textit{using the pythagorean theorem} \\\\ c^2=a^2+b^2 \qquad \begin{cases} c=\stackrel{hypotenuse}{24+x}\\ a=\stackrel{adjacent}{24}\\ b=\stackrel{opposite}{32}\\ \end{cases}\implies (24+x)^2~~ = ~~24^2+32^2 \\\\\\ (24+x)(24+x)~~ = ~~24^2+32^2\implies \stackrel{F~O~I~L}{24^2+48x+x^2}~~ = ~~24^2+32^2 \\\\\\ 48x+x^2=32^2\implies x^2+48x-32^2=0\implies x^2+48x-1024=0 \\\\\\ (x-16)(x+64)=0\implies x= \begin{cases} 16~~\textit{\Large \checkmark}\\\\ -64 \end{cases}[/tex]
notice, we didn't use -64, since the value of "x" must be a positive value.
