Verified answer

Bonjour,

87/60 = 1/2 + 1/4 + 1/3 + 1/6 + 1/5

1/2 + 1/4 + 1/3 + 1/6

= (1 x 12) / (2 x 12) + (1 x 6) / (4 x 6) + (1 x 8) / (3 x 8) + (1 x 4) / (6 x 4)

= 12/24 + 6/24  + 8/24 + 4/24

= 30/24

et

87/60 - 30/24

= (87 x 2) / (60 x 2) - (30 x 5) / (24 x 5)

= 174/120 - 150/120

= 24/120

= (24 x 1) / (24 x 5)

= 1/5

90

conseil :

calcule 1/2 + 1/4 + 1/3 + 1/6 ..

dénominateur commun : 12

= 6/12 + 3/12 + 4/12 + 2/12 = 15/12

87/60 = 15/12 + 1/?

60 est multiple de 12 = 5x12 = 60

87/60 = 75/60 + 12/60 = 15/12 + 1/5