Bonjour,
D= 4d² - 5d + 9 - 3d - 7d² - 2
= -3d² -8d +7
E = -3 + 4x - 9x² + 5x - 2x² + 2
= -11x² +9x -1
F= 13t-t² + 12 - 7t + 3t² - 4
= 2t² +6t =8
G = (22 - 4z)+ (2+5) - 8+ (- 22 + 3z² - 8) + 5z
= 22 - 4z+ 2+5 - 8- 22 + 3z² -8 + 5z
= 3z² +z-9
H = 10c-11c² + (8c² + c-25)
= 10c-11c² + 8c² + c-25
= -3c² +11c -25
I = (u² + 5u - 4) + (9u - 2u- 7)
= u² + 5u - 4 + 9u - 2u- 7
= u² +12u -11
