Bonsoir,
A = 4x² - 5x + 9 - 3x - 7x² - 2
= -3x² -8x +7
B = -3 + 4x + 9x² + 5x - 2x² + 6
= 7x² +9x +3
C = 13x - x² + 12 - 7x + 3x² - 4
= 2x² +6x +8
D = 3x - 4 - 7x - 2 + 4x - 6
= -6
E = 2x² - x + 4 - x² + 4x - 5
= x² +3x -1
F = -3 + 2x + x² - 5x + 4x² - 1
= 5x² -3x -4
G = 3× + 2 + 2x - 4 - 5x
= -2
H = -5 - 4x + 5y - 2y + 6x
=2x +3y -5
I = 5z - 4x - 3y + 5 + 4x + 6y - z
= 3y +4z +5
J = 4x² + 4y + 4z - 16 - 4x - 4y - 4z
= 4x² -4x -16
K = 12z - 4 - 5x² +1z + 3z + y - 5w
= 5x² +Y +15z -5w -4
