Question

1 si 2/5+3 si 1/10 =
3si 1/3+2 si 2/5=
3 si 5/21+1di 7/12=
5 si 5/6-1si 1/6=
4 si 5/18-3 si 1/9=
7 si 1/7-4 si 2/3=
9 si 2/3-8si1/4=
rezultat forma ireductibila

Answer 1

/=fractie
Ca exemplu: 1 si 2/5=(5x1+2)/5=7/5


1 si 2/5+3 si 1/10 =7/5+31/10=(14+31)/10=45/10=9/2
3si 1/3+2 si 2/5=10/3+12/5=(50+36)/15=86/15
3 si 5/21+1di 7/12=68/21+19/12=(4x68+7x19)/84=(272+133)/84=405/84=135/28

5 si 5/6-1si 1/6=35/6-7/6=(35-7)/6=28/6=14/3

4 si 5/18-3 si 1/9=77/18-28/9=(77-28x2)/18=(77-56)/18=21/18=7/6

7 si 1/7-4 si 2/3=50/7-14/3=(3x50-7x14)/21=(150-98)/21=52/21

9 si 2/3-8si1/4=29/3-33/4=(29x4-33x3)/12=(116-99)/12=17/12