Respostas

2014-03-14T19:43:48-03:00
2.16 - 7.4 - 18
32 - 28 -18
-14
2014-03-14T19:44:33-03:00
2x² - 7x - 18 

2.(4)² - 7.4 - 18

2.16 - 28 - 18

32 - 28 - 18 = -14