bonjour
A. (x-9)² = 16
( x - 9 )² - 16 = 0
( x - 3 - 4 ) ( x - 3 + 4 ) = 0
( x - 7 ) ( x + 1 ) = 0
x = 7 ou - 1
B. x²=81
x ² - 81 = 0
( x - 9 ) ( x + 9 ) = 0
x = 9 ou - 9
C. (2-3x)² = 1
( 2 - 3 x )² - 1
= ( 2 - 3 x - 1 ) ( 2 - 3 x + 1 )
= ( - 3 x + 1 ) ( - 3 x + 3 )
= - 3 ( - 3 x + 1 ) ( x - 1 )
D. x²=2
x = √2 ou - √2
E. (4x-1)2=9
= ( 4 x - 1 )² - 9 = 0
= ( 4 x - 1 - 3 ) ( 4 x - 1 + 3 )
= ( 4 x + 4 ) ( 4 x + 2 )
2 ( 2 x + 2 ) ( 2 x + 1 )
