Sagot :
Réponse :
bonjour
n) x² + 8 x = 0
x ( x + 8 ) = 0
x = 0 ou - 8
p) x² - 36 = 0
( x - 6 ) ( x + 6 ) = 0
x = 6 ou - 6
q) 9 x² - 100 = 0
( 3 x - 10 ) ( 3 x + 10 ) = 0
x = 10/3 ou - 10/3
r) 49 x² + 1 = 65
49 x² = 64
49 x² - 64 = 0
( 7 x - 8 ) ( 7 x + 8 ) = 0
x = 8/7 ou - 8/7
Explications étape par étape
Réponse :
Explications étape par étape
Bonsoir
n) (x*x)+ 8x = 0
x^2 + 8x = 0
x(x + 8) = 0
x = 0 ou x + 8 = 0
x = 0 ou x = -8
p) (x*x)- 36=0
x^2 - 36 = 0
x^2 - 6^2 = 0
(x - 6)(x + 6) = 0
x - 6 = 0 ou x + 6 = 0
x = 6 ou x = -6
q) 9*(x*x)- 100 = 0
9x^2 - 100 = 0
(3x)^2 - 10^2 = 0
(3x - 10)(3x + 10) = 0
3x - 10 = 0 ou 3x + 10 = 0
3x = 10 ou 3x = -10
x = 10/3 ou x = -10/3
r) 49*(x*x) + 1 = 65
49x^2 + 1 - 65 = 0
(7x)^2 - 64 = 0
(7x)^2 - 8^2 = 0
(7x - 8)(7x + 8) = 0
7x - 8 = 0 ou 7x + 8 = 0
7x = 8 ou 7x = -8
x = 8/7 ou x = -8/7