Sagot :
Développons :
x(x+1)=3-x
x^2 + x = 3-x
x^2 +2x -3 = 0
DELTA : b^2 - 4 ac
2^2 - 4 * 1 * (-3) = 16
x1 = -b-sqrd(delta) / 2a = -2-4/2*1 = -3
x2 = -b+sqrd(delta) / 2a = -2+4/2*1 = 1
Les racines sont 1 et -3
x(x+1)=3-x
x^2 + x = 3-x
x^2 +2x -3 = 0
DELTA : b^2 - 4 ac
2^2 - 4 * 1 * (-3) = 16
x1 = -b-sqrd(delta) / 2a = -2-4/2*1 = -3
x2 = -b+sqrd(delta) / 2a = -2+4/2*1 = 1
Les racines sont 1 et -3