Respostas

2014-05-23T16:37:26-03:00

x²+10x+21

100 - 84
delta = 16

-10 + 4 / 2 = -3
-10 - 4 / 2 = -7

{-3, -7}
2014-05-23T16:55:54-03:00
Nessa questão usaremos a formula de bhaskara.
x= -b±√b²-4ac/2a
x= -10±√10²-4·1·21/2·1
x= -10±√100-84/2
x= -10±√16/2
x'= -10+4/2
x'= -6/2
x'= -3
x''= -10-4/2
x''=-14/2
x''= -7
{-3,-7}