a)1/6+1/9 б)2/9+5/6 в) 2/9+3/8 г) 2/10+6/15

A)) 1/6+ 1/9= (1•6)/(6•6)+ (1•4)/(9•4)= 6/36+ 4/36= (6+4)/36= 10/36= (10:2)/(36:2)= 5/18. Б)) 2/9+5/6= (2•4)/(9•4)+ (5•6)/(6•6)= 8/36+ 30/36= (8+30)/36= 38/36= 1 целая 2/36= 1 целая (2:2)/(36:2)= 1 целая 1/18 В)) 2/9+3/8= (2•8)/(9•8)+ (3•9)/(8•9)= 16/72+ 27/72= (16+27)/72= 43/72Г)) 2/10+ 6/15= (2•3)/(10•3)+ (6•2)/(15•2)= 6/30+ 12/30= (6+12)/30= 18/30= (18:6)/(30:6)= 3/5.