Bonjour qui pourrait m'aider sur l'exercice addition des fractions svp ??

Bonjour,

a. 3/7 + 2/7 = 5/7

b. 4/9 + 2/9 = 6/9 = 3 x 2 / 3 x 3 = 2/3

c. 5/11 + 2/11 = 7/11

d. 4/15 + 2/15 = 6/15 = 3 x 2 / 3 x 5 = 2/5
                        
                              -------------

a. 1/3 + 5/6 = 1 x 2 / 3 x 2 + 5/6 = 2/6 + 5/6 = 7/6

b. 3/4 + 1/12
= 3 x 3 / 4 x 3 + 1/12
= 9/12 + 1/12
= 10/12
= 2 x 5 / 2 x 6
= 5/6

c. 16/19 + 3/4
= 16 x 4 / 19 x 4 + 3 x 19 / 4 x 19
= 64/76 + 57/ 76
= 121/76

d. 2/15 + 7/25
= 2 x 5 / 15 x 5 + 7 x 3 / 25 x 3
= 10/75 + 21/ 75
= 31/75

e. 57/95 + 95/38
= 57 x 2 / 95 x 2 + 95 x 5 / 38 x 5
= 114/190 + 475/190
= 589/190
= 19 x 31 / 19 x 10
= 31/10

f. 3/25 + 24/30
= 3 x 30 / 25 x 30 + 24 x 25 / 30 x 25
= 90/750 + 600/750
= 690/750
= 30 x 23 / 30 x 25
= 23/25
 
                            ---------------

a. 3/7 + 2/21 + 5/14
= 3 x 6 / 7 x 6 + 2 x 2 / 21 x 2 + 5 x 3 / 14 x 3
= 18/42 + 4/42 + 15/42
= 37/42

b. 11/12 + 13/24 + 5/3
= 11 x 2 / 12 x 2 + 13/24 + 5 x 8 / 3 x 8
= 22/24 + 13/24 + 40/24
= 75/24
= 3 x 25 / 3 x 8
= 25/8

c. 16/19 + 23/38 + 12/95
= 16 x 10 / 19 x 10 + 23 x 5 / 38 x 5 + 12 x 2 / 95 x 2
= 160/190 + 115/190 + 24/190
= 299/190

d. 13/5 + 13/10 + 13/4
= 13 x 8 / 5 x 8 + 13 x 4 / 10 x 4 + 13 x 10 / 4 x 10
= 104/40 + 52/40 + 130/40
= 286/40
= 2 x 143 / 2 x 20
= 143/20

e. 7/22 + 15/22 + 22/55
= 7/22 + 15/22 + 11 x 2 / 11 x 5
= 7/22 + 15/22 + 2/5
= 7 x 5 / 22 x 5 + 15 x 5 / 22 x 5 + 2 x 22 / 5 x 22
= 35/110 + 75/110 + 44/110
= 154/110
= 2 x 143 / 2 x 20
= 143/20

f. 26/7 + 36/14 + 120/21
= 26 x 6 / 7 x 6 + 36 x 3 / 14 x 3 + 120 x 2 / 21 x 2
= 156/42 + 108/42 + 240/42
= 504/42
= 42 x 12 / 42 x 1
= 42
 
                                    ----------------------

a. 16/24 - 2/9
= 16 x 3 / 24 x 3 - 2 x 8 / 9 x 8
= 48/72 - 16/72
= 32/72
= 8 x 4 / 8 x 9
= 4/9

b. 32/48 - 5/12
= 32/48 - 5 x 4 / 12 x 4
= 32/48 - 20/48
= 12/48
= 12 x 1 / 12 x 4
= 1/4

c. 14/63 - 1/5
= 14 x 5 / 63 x 5 - 1 x 63 / 5 x 63
= 70/315 - 63/315
= 7/315
= 7 x 1 / 7 x 45
= 1/45

d. 33/55 - 28/56
= 33 x 56 / 55 x 56 - 28 x 55 / 56 x 55
= 1848/3080 - 1540/3080
= 308/3080
= 308 x 1 / 308 x 10
= 1/10