Răspuns:
Explicație pas cu pas:
3/7 + 2/7 - 4/7 = (3+2-4)/7 = 1/7
9/12 - 6/12 + 4/12 = (9-6+4)/12 = 7/12
1 - 2/8 + 6/8 = 8/8 - 2/8 + 6/8 = (8-2+6)/8 = 12/8⁽⁴ = 3/2
1 + 7/9 -8/9 = 9/9 + 7/9 - 8/9 = (9+7-8)/9 = 8/9
1 - (2/7 +4/7 -3/7) = 7/7 - (2+4-3)/7 = 7/7 - 3/7 = (7-3)/7 = 4/7
1 + (11/4 - 3/4 -2/4) = 4/4 + (11-3-2)/4 = 4/4 + 6/4 = (4+6)/4 = 10/4⁽² = 5/2
2 - (7/13 + 2/13 - 3/13) = 26/13 - (7+2-3)/13 = 26/13 - 6/13 =
= (26-6)/13 = 20/13
