Bonsoir;
on factorise:
J= (4-x)(2x +1)-(2x + 1)²
= (2x+1) ( 4-x -2x -1)
= (2x+1) ( -3x -3)
L = -2(3x+1)+(3x + 1)² - (3x +1)(x +3)
= (3x+1) ( -2 +3x+1 -x -3)
= (3x+1)( 2x -4)
0=(5-x)(-3-4x)-(2-7x) (5-x)
= (5-x) ( -3-4x -2 +7x)
= (5-x) ( +3x -5)
R=(5-x)²-(5-x)
(5-x) ( 5-x -1)
= (5-x)( 4-x)
