Répondre :
A = t²+ 81+18t
=(t+9)²
B = 4x²-4xy+y²
=(2x-y)²
C = 81 +16y²-72y
=(9-4y)²
D = x²+36-12x
=(x-6)²
=(t+9)²
B = 4x²-4xy+y²
=(2x-y)²
C = 81 +16y²-72y
=(9-4y)²
D = x²+36-12x
=(x-6)²