4/10=2/5 знаменатель 55
2/5 + 49/55=22/55+49/55=71/55=1 16/55
4/10+49\55= 220+490/550=710/550=1 160/550= 1 16/55
4/10=2/5 знаменатель 55
2/5 + 49/55=22/55+49/55=71/55=1 16/55
4/10+49\55= 220+490/550=710/550=1 160/550= 1 16/55