Sagot :
bonjour
- 2 - x = 0
- x = 2
x = - 2
2 x - 4 = 0
2 x = 4
x = 2
- 5 + x = - 2 x + 3
x + 2 x = 3 + 5
3 x = 8
x = 8/3
4 x - 2 = 0
4 x = 2
x = 2/4 = 1 /2
2 x - 6 = 8
2 x = 8 + 6
2 x = 14
x = 7
- 5 x = - 4
x = 4/5
- 2 x - 6 = 3 x + 4
- 2 x - 3 x = 4 + 6
- 5 x = 10
x = - 2
2 x + 6 - 5 x + 5 = 2
- 3 x = 2 - 6 - 5
- 3 x = - 9
x = 3
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cahier = x
livre = x + 200
3 x + 2 ( x + 200 ) = 1 900
3 x + 2 x + 400 = 1 900
5 x = 1 900 - 400
5 x = 1 500
x = 300
cahier = 300 D et livre = 500 Dh
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côté triangle = x donc périmètre = 3 x
côté carré = x - 2 donc périmètre = 4 ( x - 2 ) = 4 x - 8
3 x = 2 ( 4 x - 8 )
3 x = 8 x - 16
3 x - 8 x = - 16
- 5 x = - 16
x = 16/5 = 3.2 cm