Réponses

  • Utilisateur Brainly
2013-03-25T20:29:36+01:00

Equation :

3(x+5)=(x+2)(x-5)-x²

3x +15 = x*x + x *-5 +2 *5 +2 *-5 -x²

3x +15 = x² -5x +10 -10 -x²

3x + 15 =  -5x

3x +15 + 5x =0

8x + 15 =0

8x = -15

x = -15/8

 

Inequation :

5x+25>7x+5

5x + 25 - 7x - 5 > 0

-2x + 20 > 0

-2x > - 20

-x < -20/2

x < 10