М- 49=34+7, a+23=5*8, x\7=18\3,
M-49=34+7 m-49=41 m=41+49 m=90 a+23=5*8 a+23=40 a=40-23 a=17 x/7=18/3 3x=18*7 3x=126 x=126:3 x=42