Answered

Bonjour, pouvez-vous m aider à résoudre les équations suivantes s'il vous plait :
2x + 10 = 0
2x + 10 = 5x - 2
2x - 3(x+2) = 6 + 5(x-4)
-1/7x + 1 = -x + 1/7

Sagot :

HASYATA

Bonjour !

2x + 10 = 0

<=> (2x + 10) - 10 = (0) - 10

<=> 2x = -10

<=> (2x) / 2 = (-10) / 2

<=> x = -5

2x + 10 = 5x - 2

<=> 2x + 10 = 5x - 2

<=> 2x + 10 - 10 = 5x - 2 - 10

<=> 2x = 5x - 12

<=> 2x - 5x = 5x - 12 - 5x

<=> -3x = -12

<=> -3x / (-3) = -12 / (-3)

<=> x = 4

2x - 3(x+2) = 6 + 5(x-4)

<=> 2x - 3x - 6 = 6 + 5x - 20

<=> -x - 6 = 5x - 14

<=> -x - 6 - 5x = 5x - 14 - 5x

<=> -6x - 6 = -14

<=> -6x - 6 + 6 = -14 + 6

<=> -6x = -8

<=> -6x / (-6) = -8 / (-6)

<=> x = 8/6 = 4/3

-1/7x + 1 = -x + 1/7

<=> (-1/7x + 1) *  7 = (-x + 1/7) * 7

<=> -x + 7 = -7x + 1

<=> -x + 7 + 7x = -7x + 1 + 7x

<=> 6x + 7 = 1

<=> 6x + 7 - 7 = 1 - 7

<=> 6x = -6

<=> x = -6 / 6 = -1

Voilà !