Bonsoir

Exercice 22:

A=2/5x-7/5x

A=-5/5x

A=-x

B=-7/12x²-8/18x²

B=-21/36x²-16/36x²

B=-37/36x²

C=1/3x²-5/6x²-3x+6-2/3-15

C=2/6x²-5/6x²-3x+18/3-2/3-45/3

C=-3/x²-3x+-29/3

D=-5√2-15√2+2/9√2+10.5√7-18.3√7

D=-45/9√2-135/9√2+2/9√2-7.8√7

D=-178/9√2-7.8√7

Exercice 23:

A=7(x²+4)

B=1/9(4x²-49/9)

je te laisse essayer de faire le reste

EX22

1) A = (2/5) x - (7/5) x = (2 x - 7 x)/5 = - 5 x/5 = - x

2) B = - 7/12) x² - (8/18) x² = - 7/12) x² - (4/9) x² = - 21/36) x² - (16/36) x² = - 37/36) x²

3) C = 1/3) x² - 3 x + 6 - 2/3 - (5/6) x² - 15

       = 2/6) x² - (5/6) x² - 3 x + 18/3 - 2/3 - 45/3

       = - 3/6) x² - 3 x  - 29/3

       = - 3/6) x² - 18/6) x - 58/6

       = 1/6(- 3 x² - 18 x - 58)

D = - 5√2 + 10.5√7 - 15√2 - 18.3√7 + (2/9)√2

  = - 20√2 - 7.8√7 + (2/9)√2

  = - 180√2/9 - 70.2√7/9 + (2/9)√2

  = - 178√2/9 - 70.2√7/9

  = 1/9(- 178√2 - 70.2√7)