Répondre :
O=100 -60x +9x²
=(10-3x)²
p=4x² +12x-1
=2x(2x+6)-1
q=4x²+4x+1
=(2x+1)²
r=36x²+12x-1
=12x(3x-1)
s=36x²+12×-1
==12x(3x-1)
t=49x²-(4x+5)²
=(7x-4x-5)(7x+4x+5)
=(3x-5)(11x+5)
u=-9x² +16
non factorisable
=(10-3x)²
p=4x² +12x-1
=2x(2x+6)-1
q=4x²+4x+1
=(2x+1)²
r=36x²+12x-1
=12x(3x-1)
s=36x²+12×-1
==12x(3x-1)
t=49x²-(4x+5)²
=(7x-4x-5)(7x+4x+5)
=(3x-5)(11x+5)
u=-9x² +16
non factorisable