4/13(6,5n-3 1/4m)-3,2(5/8n-0,5m)

4/13*6,5n-4/13*3 1/4m-3,2*5/8n+3,2*0,5m=4/13*65n10n=2n4/13*3 1/4 m=4/13*13/4m=m3,2*5/8n=32/10*5/8n=2n3,2*0,5m=1,6m2n-m-2n+1,6m=0,6m