Răspuns:
Explicație pas cu pas:
a/b = 2/3
b/c = 4/9
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a = 2b/3
2a = 4b/3
2a/3b = 4b/3 : 3b = 4b/3 * 1/3b = 4/9
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a + b = 2b/3 + b = 2b/3 + 3b/3 = 5b/3
(a + b)/2b = 5b/3 : 2b = 5b/3 * 1/2b = 5/6
_______________
c = 9b/4
a/c = 2b/3 : 9b/4 = 2b/3 * 4/9b = 8/27
