Réponses

2013-05-30T17:05:20+02:00

Bonjour

 

a)

7y/4 +6 = 24/5 - 21y

32y/20  + 30/5 = 96/5 - 105y/5

32y +105y = 96 -30

137y = 66

y = 66/137

 

b)

3a/4 +3a = 6 +14a/4

3a/4 + 12a/4 = 24/4 +14a/4

3a+12a -24a -14a = 24

-23 a = 24

a = -24/23

 

c)

21b/2 +3/5 = 6/5 - 28b

105b/10 +6/10 = 12/10 - 280b/10

105b +280b = 12 -6

385b= 6

b = 3/385

 

d)

15x/7 +21/2 = (3x -9)/2

30x/14 + 147/14 = 21x/7 -63/7

30x -21x = -63 -147

9x = 210

x = 210/9 ou 70/3