bonjour
x ² = 25
2 méthodes possibles
x² - 25 = 0
( x - 5 ) ( x + 5 ) = 0
donc x = 5 ou - 5
x² = 25
x = √25 ou - √25
x = 5 ou ( - 5)
4 x² = 9
4 x² - 9 = 0
( 2 x- 3 ) ( 2 x + 3 ) = 0
x = 2/3 ou - 2/3
4 x² = 9
x² = 9/4
x = √9/4 = 3/2
x = - √9/4 = - 3/2
x² = 49
x = √49
x = 7
x = - √49
x = - 7
( x - 1 )² = 4
( x - 1 )² - 4 = 0
( x - 1 - 2 ) ( x - 1 + 2 ) = 0
( x - 3 ) ( x + 1 ) = 0
x = 3 ou x = - 1
x² = 1
x = √1
x = - √1