Réponse :
bonjour
Explications étape par étape
ex 1
A=(x+5)²+(x+1)(x-5)
x²+10x+25+x²-5x+x-5
2x²+6x+20
B=(2/3t+1/5)²
4/9t²+4/15t+1/25
C=(4y+7)(4y-7)-(y+1)(y-1)
16y²28y+28y-49-y²+1y-1y+1
15y²-48
ex 2
E=(x-5)²+(x+1)(x-5)
(x-5)(x+1+x-5)
(x-5)(2x-4)
F=(2x-1)(x+2)-(2x-1)²
(2x-1)(x+2-2x+1)
(2x-1)(-x+3)
H=(x-1)²-25
(x-1-5)(x-1+5)
(x-6)(x+4)
I=(x-2)²-(3-5)²
(x-2-3+5)(x-2+3-5)
x(x-4)