Question

M(3-4m)=7+4(8-m2) m=?

Answer 1

$m(3-4m)=7+4(8-m^2) \\ 3m-4m^2=7+32-4m^2 \\ 3m-4m^2+4m^2=7+32 \\ 3m=39 \\ m=\frac{39}{3} \\ m=13$