Respostas

2014-03-30T16:22:39-03:00
(3x² - 5x + 2 ) + ( x² + 6x -4 ) + ( 5x - 7 )
3x² -5x +2 +x² + 6x -4 +5x -7=
4x² + 6x -9
2014-03-30T16:27:32-03:00
(3x² - 5x + 2 ) + ( x² + 6x -4 ) + ( 5x - 7 )
(9x-5x+2)+(-5x-4)- (5x-7)
(4x+2)+(-5x-4) -(5x-7)
4x-5x+5x=2+(-4)-(7)
-1x+5x=-2+7
4x=5
x=5/4
acredito que esse seja o resultado!