Given
[tex]4m^2n = 49[/tex]
To solve for m, we make m the subject of the formula as follows:
[tex]4m^2n = 49 \\ \\ m^2= \frac{49}{4n} \\ \\ m=\pm
\sqrt{\frac{49}{4n}} =\pm \frac{7}{2 \sqrt{n} } \\ \\ m=\pm\frac{7}{2
\sqrt{n} }\times \frac{ \sqrt{n} }{ \sqrt{n} } \\ \\ m=\pm\frac{7
\sqrt{n} }{2n }[/tex]