Răspuns:
Explicație pas cu pas:
a)
1/10 + 1/9 = 9/90 + 10/90 = 19/90
4/9 + 55/90 = 40/90 + 55/90 = 95/90
19/90 : 95/90 = 19/90 x 90/95 = 19/95 = 1/5
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b)
(11/24 + 11/36) : 11/6 = (33/72 + 22/72) : 11/6 = 55/72 : 11/6 = 55/72 x 6/11 = 5/12
(11/6 - 5/9) : 23/5 = (33/18 - 10/18) : 23/5 = 23/18 : 23/5 = 23/18 x 5/23 = 5/18
