Réponse:
a. E=49x²- (4x -5)²
=49x²- [ (4x)²-2×4x×5+5² + 5²]
=49x²-(16x²-40x+25)
=49x²-16x²+40x-25
=33x²+40x-25
b. E=49x²-( 4x-5)²
=(7x )²-(4x-5)²
=(7x -(4x-5)) (7x+ (4x-5))
=(7x-4x+5)(7x+4x-5)
=(3x+5)(11x-5)
d.E=49×0²-(4×0-5)²
=0 - (-5)²
= 0- 25
= -25
j'espère avoir aider
