Réponse :
bonjour
Explications étape par étape
A = 3+5/4x(2-1/5)
2-1/5=10/5-1/5=9/5
5/4x9/5=45/20=(9x5)/(5x4)=9/4
3+9/4=12/4+9/4=21/4
B= 26/3 × 1/13 + 5/13 × 39/25=26/39+195/325
26/39=(13x2)/(13x3)=2/3
195/325=(39x5)/(65x5)=39/65=(13x3)/(13x5)=3/5
2/3+3/5=(2x5)/(3x5)+(3x3)/(5x3)=10/15+9+15=19/15
C= (11/6 - 3/8) + (4/9 + 2/3)
11/6-3/8=(11x4)/(6x4)-(3x3)/(8x3)=44/24-9/24=35/24
4/9+2/3=4/9+(2x3)/(3x3)=4/9+6/9=10/9
35/24+10/9=(35x3)/(24x3)+(10x8)/(9x8)=105/72+80/72=185/72
D = (11/3 - 2)/(25/6)
11/3-6/3=5/3
5/3x6/25=30/75=(15x2)/(15x5)=2/5