Sagot :
Réponse :
bonsoir
A (x) = x² + 5 x - 6
B (x) = x² + 6 x - x - 6 = x² + 5 x - 6
C (x) = x² + 10 x /2 + 25/4 - 49/4 = x² + 5 x - 24/4 = x² + 5 x - 6
A ( √2)= ( √2)² + 5 √2 - 6 = 2 + 5 √2 - 6 = - 4 + 5 √2
A ( √3) = 3 + 5 √3 - 6 = - 3 + 5 √3
A ( 1 ) = 1 + 5 - 6 = 0
f (x) = 0
( x - 1 ) ( x + 6 ) = 0
x = 1 ou - 6
f (x) = - 6
x² + 5 x - 6 = - 6
x² + 5 x = 0
x ( x + 5 ) = 0
x = 0 ou - 5
f (x) = 15/4
( x + 5/2 )² - 49/4 = 15/4
( x + 5 /2 )² - 49/4 - 15/4 = 0
( x + 5 /2 )² - 64/4 = 0
( x + 5/2 - 8/2 ) ( x + 5/2 + 8/2 ) = 0
'( x - 3 /2 ) ( x + 13 /2 ) = 0
x = 3/2 ou - 13/2
Explications étape par étape :