Question

49m^2-n^2 дробь 3mn^2-21m^2n
сократите дробь

Answer 1

$<var>\frac{49m^{2}-n^{2}}{3mn^{2}-21m^{2}n}= \\ \\ \frac{(7m-n)(7m+n)}{3mn(n-7m)}= \\ \\ \frac{(7m-n)(7m+n)}{-3mn(7m-n)}= \\ \\ -\frac{7m+n}{3mn}</var>$