bonjour
E= ( 2+3b) (-7b -4)
E = - 14 b - 8 - 21 b² - 12 b
E = - 21 b² - 26 b - 8
F= ( 3 - 5x) (4- 7x)
F = 12 - 21 x - 20 x + 35 x²
F = 35 x² - 41 x + 12
G = ( -7y - 3) ( 2y - 7 )
G = - 14 y² + 49 y - 6 y + 21
G = - 14 y² + 43 y + 21
H = ( a² - 3) (-2a + 4 )
H = - 2 a ³ + 4 a² + 6 a - 12
I = 2a ( 3a+5 ) + ( a - 3 ) (2+a)
I = 6 a² + 10 a + 2 a + a² - 6 - 3 a
I = 7 a² + 9 a - 6