Respostas

2013-05-08T10:49:46-03:00

 

 = b²-4ac

= 1²-4.1.(-56)

=1+224

=225

-b 

1 5 1
2013-05-08T12:16:10-03:00

d)x²+x-56=0
( x + 8 ) ( x - 7 ) = 0, x' = -8, x'' = -7