bonjour
4 x - 5 > 0
4 x > 5
x > 5/4
2 x + 9 < 5 x - 4
2 x - 5 x < - 4 - 9
- 3 x < - 13
x > 13/3
x² - 2 x + 1 = ( x - 1 )²
25 x² + 60 x + 36 = ( 5 x + 6 ) ²
49 x² - 64 = ( 7 x - 8 ) ( 7 x + 8 )
( x - 2 )² - 9 = ( x - 2 - 3 ) ( x - 2 + 3 ) = ( x - 5 ) ( x + 1 )
4 x - 8 = 4 ( x - 2 )
7 x² - 2 x = x ( 7 x - 2 )
2 ( x + 1 ) - x ( x + 1 ) = ( x + 1 ) ( 2 - x )
( 2 x + 1 ) ( 3 x - 4 ) + ( 3 x - 4 ) ( 5 x + 3 )
= ( 3 x - 4 ) ( 2 x + 1 + 5 x + 3 )
= ( 3 x - 4 ) ( 7 x + 4 )
