Réponse :
bonjour
A = ( 7 x - 2 )² = 16
a = ( 7 x - 2 )² - 16 = 0
( 7 x - 2 - 4 ) ( 7 x - 2 + 4 ) = 0
( 7 x - 6 ) ( 7 x + 2 ) = 0
x = 6/7 ou - 2 /7
x² + 25 = 0
x ² = - 25
pas de solution dans R
( x + 4 ) ( 2 x - 1 ) + x² - 16 = 0
( x + 4 ) ( 2 x - 1 ) + 1 ( x - 4 ) ( x + 4 ) = 0
( x + 4 ) ( 2 x - 1 + x - 4 ) = 0
( x + 4 ) ( 3 x - 3 ) = 0
x = - 4 ou 1
- 2 x /3 + 1 = 2 /5
- 10 x /15 + 15/15 = 6 /15
- 10 x = 6 - 15
- 10 x = - 9
x = 9/10
- 2 /3 + x - 1/3 = 2/5 - x
- 10/15 + 15x /15 - 5 /15 = 6 /15 - 15 x /15
15 x + 15 x = 6 + 10 + 5
30 x = 21
x = 21/30 = 7/10
Explications étape par étape
