Respostas

2014-07-08T12:06:54-03:00
2x - 4 -x² + 2x > 0
4x - x² -4

-x²+4x-4
4²-4*(-1)*(-4)
16-16 = 0

2x²-6x-6x+18
2x²-12x+18

12²-4*2*18
144-144 = 0

2x - 4x² -1+2x
-4x² + 4x -1
16-4*(-4)*(-1)
16-16 = 0