Question

Сократите дробь 9-m^2/m^2+m-12

Answer 1

$\frac{9-m^2}{m^2+m-12} =\frac{(3-m)(3+m)}{m^2+4m-3m-12} =\frac{(3-m)(3+m)}{m(m+4)-3(m+4)} =\frac{(3-m)(3+m)}{(m+4)(m-3)} =-\frac{m+3}{m+4}$