Răspuns:
3a) introducem intregii in fractie
3si 1/5=(3·5+1)/5=16/5
8si3/4=35/4
16/5·35/4=simplificam pe diagonala=20
b) 1si2/7=9/7
113/15=28/15
9/7·28/15=36/15 = 2 intregi 6/15
simplificam pe 28 si 7
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4a) 12/20·4/6·5/22=2/22=1/11
se simplifica termenii pe diagonala
b) 22/36·1/3·81/11= 2/36·27 =1/18·27=1/2·3=3/2
