Réponse:

E =x²+ 2x + 1 + 7x ( 2 - x )

E = x² + 2x + 1 + 14x - 7x²

E = x² + 16x + 1 - 7x²

E = - 6x² + 16x + 1

F = 2x² - x + 6x - 3 - 3x ( 2x + 5 )

F = 2x² + 5x - 3 - 3x ( 2x + 5 )

F = 2x² + 5x - 3 - 6x² - 15x

F = - 4x² + 5x - 3 - 15x

F = - 4x² - 10x - 3

G = ( 4t )² - 1 - ( 3t + 2 )²

G = 4²t² - 1 - ( 3t + 2 )²

G = 16t² - 1 - ( 3t + 2 )²

G = 16t² - 1 - ( 9t² + 12t + 4 )

G = 16t² - 1 - 9t² - 12t - 4

G = 7t² - 1 - 12t - 4

G = 7t² - 12t - 5

H = ( 2s + 10 ) ( s - 5 ) + ( 4s + 3 )²

H = 2s²- 50 + ( 4s + 3 )²

H = 2s² - 50 + 16s² + 24s + 9

H = 18s² - 50 + 24s + 9

H = 18s² + 24s - 41

I = 9x² + 24x + 16 - ( 1 - 2x ) ( 6x + x )

I = 9x² + 24x + 16 - ( 6 - 11x - 2x² )

I = 9x² + 24x + 16 - 6 + 11x + 2x²

I = 9x² + 24x + 10 + 11x + 2x²

I = 9x² + 35x + 10 + 2x²

I = 11x² + 35x + 10