Bjr aide pour maths 2nd merci !

bonjour

exercice 2

(2x-1)²=4x²-4x+1

(-x+2)²=x²-4x+4

1+2x(x-2)=1+2x²-4x=2x²-4x+1

(2x-1)(2x+1)=4x²+2x-2x-1=4x²-1

exercice 3

a (7x-1)²=49x²-14x+1

b (4-3t)(4+3t)=16+12t-12t-9t²=-9t²+16

c (3s+2)(2s-3)=6s²-9s+4s-6=6s²-5s-6

d 7(x-1)²=7(x²-2x+1)=7x²-14x+7