Respostas

2013-08-31T20:29:15-03:00
9= n²-3n/2(multiplica cruzado)
18=n² -3n
n²-3n=18
n²-3n-18=0
Δ= b²-4ac
Δ=(-3)²-4(1)(-18)
Δ=9+72
Δ=81
x=-b±√Δ/2
x= 3±√81/2
x=3±9/2
x'= 3+9/2. x'=6
x"=3-9/2. x"=-3
1 5 1