Răspuns:
Explicație pas cu pas:
i)
abc/999 + cab/999 + bca/999 = (abc + cab + bca)/999
abc + cab + bca = 100a + 10b + c + 100c + 10a + b + 100b + 10c + a
= 111a + 111b + 111c = 111(a + b + c)
fractia devine
111(a + b + c)/999 = (a + b + c)/9
_____________________
j)
(5a + 3 - 3a + 1)/(3a + 6) = (2a + 4)/(3a + 6) = 2(a + 2)/3(a + 2) = 2/3
