Răspuns:
Explicație pas cu pas:
4/5 - a/10 = 7/10
8/10 - a/10 = 7/10
a/10 = 8/10 - 7/10 = 1/10
a = 1
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5/a + 4/3 = 17/9
5/a + 12/9 = 17/9
5/a = 17/9 - 12/9 = 5/9
a = 9
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11/12 + 5/a = 31/12
5/a = 31/12 - 11/12 = 20/12 = 5/3
a = 3
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a/3 + 13/18 = 19/18
a/3 = 19/18 - 13/18 = 6/18 = 1/3
a = 1
