4/9(2.7m-2 1/4 n )-4.2(5/7m-0.5n ) помогите???

Question

4/9(2.7m-2 1/4 n )-4.2(5/7m-0.5n ) помогите???

Answer 1

4/9 (27/10m-9/4n)=
6/5m-n=1.2m-n

21/5 (5/7m-1/2n)=
3m-21/10n=3m-2.1n
1.2m-n-3m+2.1n=1.1n-1.8m