Bonsoir, j’aimerais juste savoir si j’ai bon Simplifier : A= 15/20 = 34=0.75 B=14/40=2/7 C=220/260=11/13 D=630/810=7/9 E=560/480=7/6 Calculer : 1/2+3/2 = 2 - 3/

Bonsoir !
a = 15/20 = ( 15 ÷ 5 ) / ( 20 ÷ 5 ) = 3/4
b = 14/40 = ( 14 ÷ 2 ) / ( 40 ÷ 2 ) = 7/20
c = 220/260 = ( 220 ÷ 20 ) / ( 260 ÷ 20 ) = 11/13
d = 630/810 = ( 630 ÷ 90 ) / ( 810 ÷ 90 ) = 7/9
e = 560/480 = ( 560 ÷ 80 ) / ( 480 ÷ 80 ) = 7/6

• 1/2 + 3/2 = 4/2
• (-3/11) + 1/22 =
(-3/11) = (-6/22)
(-6/22) + 1/22 = (-5/22)
• (-5/4) - 5/6 = (-25/12)
(-5/4) = (-15/12)
5/6 = 10/12
(-15/12) - 10/12 = (-25/12)
• 3/5 - 2/7
3/5 = 3/5 × 7/7 = 21/35
2/7 = 2/7 × 5/5 = 10/35
21/35 - 10/35 = 11/35
• 5 - 6/7
5 = 5/1 = 5/1 × 7/7 = 35/7
35/7 - 6/7 = 29/7

Bonne soirée !

Bonjour,

A= 15/20 
A = (5 x 3) / (5 x 4)
A = 3/4

B=14/40
B = (2 x 7) / (2 x 20)
B = 7/20

C=220/260
C = (20 x 11) / (20 x 13)
C = 11/13

D=630/810
D = (90 x 7) / (90 x 9)
D = 7/9

E=560/480
E = (80 x 7) / (80 x 6)
E = 7/6


1/2+3/2
= 4/2
= (2 x 2) / (2 x 1)
= 2

- 3/11 + 1/22
= (- 3 x 2) / (11 x 2) + 1/22
= - 6/22 + 1/22
= - 5/22

- 5/4 - 5/6
= (- 5 x 3) / (4 x 3) - (5 x 2) / (6 x 2)
= - 15/12 - 10/12
= - 25/12

3/5 - 2/7
= (3 x 7) / (5 x 7) - (2 x 5) / (7 x 5)
= 21/35 - 10/35
= 11/35 

5 - 6/7
= (5 x 7) / (1 x 7) - 6/7
= 35/7 - 6/7
= 29/7