Pouvez-vous m'aider c'est du A au G

a =(9x-7)²
a = 81x² -126x+49

b =(x+9)(11-5x)
b = 11x-5x²+99 -45x
b = -5x² -34x +99

c =(2x-3)(2x+3)
c = 4x²-9

d =(11+8x)²
d = 121 +176x +64x²

e =(x+1)² +7x(2-x)
e = x²+2x+1 +14x-7x²
e = -6x² +16x+1

f =(x+3)(2x-1) -3x(2x+5)
f = 2x²-x+6x-3-6x²-15x
f = -4x² -10x -3

g =(4t+1)(4t-1) -(3t+2)²
g = 16t²-1 -(9t²+12t+4)
g = 16t²-1 -9t²-12t-4
g = 7t² -12t -5