Question

 7(m+n)-3(3m+2n) Упрости

Answer 1

 7(m+n)-3(3m+2n)=7m+7n-9m-6n = -2m+n= n-2m

Answer 2

$7(m+n)-3(3m+2n)=7m+7n-9m-6n=(7m-9m)+(7n-6n)=-2m+n=n-2m$