Répondre :
(2t+1)²+4t²-1
=(2t+1)(2t+1)+(2t+1)(2t-1)
=(2t+1)(2t+1+2t-1)
=4t(2t+1)
=(2t+1)(2t+1)+(2t+1)(2t-1)
=(2t+1)(2t+1+2t-1)
=4t(2t+1)
(2t+1)²+4t²-1
=(2t+1)(2t+1)+(2t+1)(2t-1)
=(2t+1)(2t+1+2t-1)
=4t(2t+1)
=(2t+1)(2t+1)+(2t+1)(2t-1)
=(2t+1)(2t+1+2t-1)
=4t(2t+1)