Réponses

2014-03-08T16:02:22+01:00
Salut :)

a. 2x + 10 = 0
2x = -10
x = -10/2
x = (-5)

b. 40x - 22 = 10x + 8
40x - 22 -10x = 8
30x = 8 + 22
30x = 30
x = 30/30
x = 1

c. 
2/4x + 5/15 = 1/4x + 3/15
2/4x + 5/15 - 1/4x = 3/15
1/4x = 3/15 - 5/15
1/4x = -2/15
x = -2/15 x 1/4
x = -1/30
 
d. x² = 121
x = √121
x = 11

e. 2x² + 1 = 289
2x² = 289 - 1
2x² = 288
x² = 288/2
x² = 144
x = √144
x = 12

f. (x+7)² = 64

(x + 7)² = 8²
x + 7 = √8²
x + 7 = 8
x = 8 - 7
x = 1

J'espère t'avoir aidé(e)! :)