Réponses

2013-10-13T13:44:14+02:00
3y(2y-5)-4y(-y+2)=( 6y²-15y)-(-4y²+8y)=6y²-15y-4y²-8y=2y²-23y
(x+1/2)(2x-6)-(-2x+1)(x-9)
(2x²-6x+x-3)-(-2x²+18x+x-9)
2x²-6x+x-3-2x²-18x-x+9
-24x+6
Meilleure réponse !
2013-10-13T13:56:03+02:00
F = 3y ( 2y - 5 ) - 4y ( -y + 2 )
= ( 6y² - 15y ) - ( -4y² + 8y )
= 6y² - 15y - 4y² - 8y
= 2y² - 23y

G =( x + 1/2 )( 2x - 6 ) - ( -2x + 1 ) ( x - 9 )
= ( 2x² - 6x + x - 3 ) - ( -2x² + 18x + x - 9 )
= 2x² - 6x + x - 3 - 2x² - 18x - x + 9
= -24x + 6