Réponse :
On a : E = (x + 3)(x - 5) + (x + 3)(x + 4)
1 ) E = ( -2 + 3 )( -2 - 5 ) + ( -2 + 3 )( -2 + 4 )
= 4 + 10 - 6 - 15 + 4 - 8 - 6 + 12
= - 35 + 30
E = -5
2 ) E = ( 2/3 + 3 )( 2/3 - 5 ) + ( 2/3 + 3 )( 2/3 + 4 )
= ( 2+9/3 )( 2-15/3 ) + ( 2+9/3 )( 2+12/3 )
= ( 11/3 X -13/3 ) + ( 11/3 X 14/3 )
= 143/9 + 154/9
= 143+154/9
= 297/9
E = 33
3 ) E = (x + 3)(x - 5) + (x + 3)(x + 4)
= x² - 5x + 3x -15 + x² + 4x + 3x + 12
E = 2x² - 5x - 3
4 ) E = (x + 3)(x - 5) + (x + 3)(x + 4)
E = ( x + 3 )( x - 5 + x + 4 )
5 ) (x + 3)(x - 5) + (x + 3)(x + 4) = 0
( x + 3 )( x - 5 + x + 4 ) = 0
x + 3 = 0 ou x - 5 + x + 4 = 0
x = - 3 ou x = [tex]\frac{-1}{2}[/tex]
Bonne Chance !!
