Question

выполните сложение 9-m/m-9 + 9m-9/9-m найти коэффициент при m в числителе ​

Answer 1

$\displaystyle\bf\\\frac{9-m}{m-9} +\frac{9m-9}{9-m} =\frac{9-m}{m-9} -\frac{9m-9}{m-9} =\frac{9-m-9m+9}{m-9} =\\\\\\=\frac{-10m+18}{m-9}=\frac{10m-18}{9-m}\\\\k=10$

Второй способ :

$\displaystyle\bf\\\frac{9-m}{m-9} +\frac{9m-9}{9-m} =-\frac{m-9}{m-9} +\frac{9m-9}{9-m} =-1+\frac{9m-9}{9-m} =\\\\\\=\frac{-9+m+9m-9}{9-m} =\frac{10m-18}{9-m} \\\\k=10$