Răspuns:
Explicație pas cu pas: Semnul ")" e pentru amplificarea fractiei,"/ " -citesti SUPRA .Asta ca sa intelegi ce am scris :)
2)13/12 +17/24 =26/24+17/24=43/24
4)7/6+17/24=28/24+17/24= 45/24
4)11/18 +3)17/24 =44/72+51/72=95/72
12)13/10+5)17/24= 156/120+ 85/120=241/120
2)23/36+3)17/24 =46/72+51/72=97/24
2)17/60+5)17/24= 34/120+85/120=119/120
6)17/28+7)17/24=102/168+119/168=221/168