Respostas

2013-09-23T16:37:24-03:00
Δ=b²-4ac
Δ= 18²-4.1.45
Δ=324-4.1.45
Δ=324-180
Δ=144

x=-b+-√Δ  / 2a
x= -18+-√144 / 2.1
x=-18+-12  /2.1
x1= -30/2 = -12
x2= -6/2= -3

Espero ter ajudadoo..