Răspuns :
0,(7) = 7/9
0,2(7) = (27-2)/90 = 25/90 = 5/18
0,13(8) = (138-13)/900 = 125/900 = 5/36
2/19* [7/9 + 5/18] : 5/36 amplifici pe 7/9 cu 2
2/19 *[14/18 + 5/18] : 5/36 =
2/19 *19/18 : 5/36 =
1/9 * 36/5 = 4/5
0,(7) = 7/9
0,2(7) = (27-2)/90 = 25/90 = 5/18
0,13(8) = (138-13)/900 = 125/900 = 5/36
2/19* [7/9 + 5/18] : 5/36 amplifici pe 7/9 cu 2
2/19 *[14/18 + 5/18] : 5/36 =
2/19 *19/18 : 5/36 =
1/9 * 36/5 = 4/5