Sagot :
bonsoir
A = 3 - ( 2x²- 1 ) + ( x + 2 ) - ( 3x - 5x )
= 3 - 2 x² + 1 + x + 2 - 3 x + 5 x
= - 2 x² + 3 x + 6
B = -3 ( -2x - 3 ) = 6 x + 9
C = 2x ( -3x + 4 ) = - 6 x² + 8 x
D = ( 1 - 3x ) ( 1 + 3x ) = 1 - 9 x²
E = ( - x + 3 ) ( 2 - x ) = - 2 x + x² + 6 - 3 x = x² - 5 x + 6
Bonsoir,
Développer les expressions:
A = 3 - ( 2x²- 1 ) + ( x + 2 )- ( 3x - 5x ) = 3-2x²+1+x+2-3x+5x= -2x²+3x+6
B = -3 ( -2x - 3 ) = 6x+9
C = 2x ( -3x + 4 ) = - 6x²+8x
D = ( 1 - 3x ) ( 1 + 3x ) = 1-3x+3x-9x²= -9x²+1
E = ( - x + 3 ) ( 2 - x ) = -2x+6+x²-3x= x²-5x+6