Sagot :
bonjour,
F = 9 x² - 48 x+ 64
F = ( 3 x - 8 )²
G = ( 3 x - 7 )² - 1
G = ( 3 x - 7 - 1 ) ( 3 x - 7 + 1 )
G = ( 3 x - 8 ) ( 3 x - 6 )
H = ( 3 x - 8 )² + ( 3 x - 8 ) ( 3 x - 6 )
H = ( 3 x - 8 ) ( 3 x - 8 + 3 x - 6 )
H = ( 3 x - 8 ) ( 6 x - 14 )
H = 0 quand l'un des facteurs est nul
H = 0 quand x = 8/3 ou 14/6 = 7/3
salut
1) F = 9x²-48x+64
F = (3x)²-2*3x*8+(8)²
F = (3x-8)²
2) G = (3x-7)²-1
G = (3x-7)²-(1)²
G = (3x-7+1)(3x-7-1)
G = (3x-6)(3x-8)
2) H = F+G
H = (3x-8)²+(3x-6)(3x-8)
H = (3x-8)(3x-8)+(3x-6)(3x-8)
H = (3x-8)(3x-8+3x-6)
H = (3x-8)(6x-14)
3) H = 0
(3x-8)(6x-14) = 0
3x-8 = 0
3x-8+8 = 0+8
3x = 8
x = 8/3
ou sinon
6x-14 = 0
6x-14+14 = 0+14
6x = 14
x = 14/6
x = 7/3