bonsoir!!! qui pourrais m aider svp 2(x+1)+5=7 2(x+1)+5=3xau caré -x+1

Bonsoir,

2(x+1)+5=7
2x + 2 + 5 = 7
2x = 7 - 2 - 5
2x = 7 - 7
x = 0

2(x+1)+5=3x²-x+1
2x + 2 + 5 = 3x² - x + 1
3x² + 2x + x = 1 - 2 - 5
3x² + 3x = - 6
3x² + 3x + 6 = 0
x (3x) + 3 (x + 2) = 0
x (3x + 2) = 0
x = 0      ou     x = 2/3