-4m-(2m-3n)=(m-n)+3n срочно !!!!!!!!!!!!
-4m-(2m-3n)=(m-n)+3n -4m-2m+3n=m-n+3n -6m+3n=m+2n -6m+3n-m-2n=0 -7m+n=0 -7m=-n 7m=n
-4m-2m+3n=m-n+3n -4m-2m-m+3n+n-3n=0 -7m+n=0