Sagot :
bonjour
A = 36 x² + 36 x + 9 + 9 - 36 x + 36 x²
A = 72 x² + 18
B = 49 x² - 25
C = x² - 64 - ( x² + 14 x + 49 )
C = x² - 64 - x² + 14 x - 49
C = 14 x - 113
Bonsoir,
A=(6x+3)²+(3-6x)²
(6x+3)(6x+3) +(3-6x)(3-6x)
= 36x² +18x + 18x + 9 + 9 - 18x -18x + 36x²
= 72x² +18
B=(7x+5)(7x-5)
49x² -35x +35x -25
= 49x² -25
C=(x+8)(x-8)–(x+7)²
= x² -8x +8x - 64 -( x² +7x +7x +49)
= x² -8x +8x - 64 - x² -7x -7x -49
= -14x - 113