Réponse :
bonjour
Explications étape par étape
P
16x²-25+(4x+5)(3x+1)
16x²-25=16x²-5²
16x²=(4x)²
(4x)²-5² =(4x+5)(4x-5)
P
(4x+5)(4x-5)+(4x+5)(3x+1)
(4x+5)[(4x-5)+(3x+1)]
(4x+5)(4x-5+3x+1)
(4x+5)(7x-4)
Q
25x²-81-7(5x+9)
25x²-81=(5x)²-9²
(5x+9)(5x-9)
Q
(5x+9)(5x-9)-7(5x+9)
(5x+9)[(5x-9)-7)]
(5x+9)(5x-9-7)
(5x+9)(5x-16)
R
25x²+70x+49-3(5x-7)
25x²+70x+49
25x²=(5x)²
49=7²
70x=2(5x)(7)
25x²+70x+49=(5x+7)²
R
(5x+7)²-3(5x+7)
(5x+7)[(5x+7)-3)]
(5x+7)(5x+7-3
(5x+7)(5x+4)
