bonsoir
B= (7x-5) (4x +3) - (5- 7x) (x + 2)
= 28 x² + 21 x - 20 x - 15 - ( 5 x + 10 - 7 x² - 14 x )
= 28 x² + x - 15 - 5 x - 10 + 7 x² + 14 x
= 35 x² + 10 x - 25
B = ( 7 x - 5 ) ( 4 x + 3 ) + ( - 5 + 7 x ) ( x + 2 )
= ( 7 x - 5 ) ( 4 x + 3 + x + 2 )
= ( 7 x - 5 ) ( 5 x + 5 )
= 5 ( 7 x - 5 ) ( x + 1 )
B = 9 x² - 24 x + 16 - ( x² + 2 x + 1 )
= 9 x² - 24 x + 16 - x² - 2 x - 1
= 8 x² - 26 x + 15
B = ( 3 x - 4 + x + 1 ) ( 3 x - 4 - x - 1 )
= ( 4 x - 3 ) ( 2 x - 5 )
