m-1\5=-8\15
8 7\22+u=5 5\33

m-1/5=-8/15m=-8/15+3/15m=-5/15m=-1/38 7/22+u=5 5/33u=5 5/33-8 7/22u=5 10/66-8 21/66u=-3 11/66u=-3 1/6