developper et reduire les expressions

a)(2x+1)² +(7x-3)(2x-5) b)-4(2x-3)+(5x-4)² c)-(2x-4)-(7x-3)(7x+3)

factoriser le plus possible et reduire les expressions suivantes

a)14a+21 b)6x²+12x c)(7x+1)(2x+3)+(7x+1)(5x-3)

d)(2x+1)²-(2x+1)(7x-4)

1

Réponses

2013-11-09T11:03:28+01:00
(2x+1)²+(7x-3)(2x-5)
4x²+4x+1+14x²-35x-6x+15
18x²-37x+16

-4(2x-3)+(5x-4)²
-8x+12+25x²-40x+16
25x²-48x+28

-(2x-4)-(7x-3)(7x+3)
-2x+4-(49x²+21x-21x-9)
-2x+4-49x²-21x+21x+9
-49x²-2x+13

14a+21=7(2a+3)
6x²+12x=6x(x+2)
(7x+1)(2x+3)+(7x+1)(5x-3)
(7x+1)(2x+3+5x-3)
(7x+1)7x
(2x+1)²-(2x+1)(7x-4)
(2x+1)(2x+1-7x+4)
(2x+1)(-5x+5)