Question

Resolva a equação x ao quadrado-3x-18=0 usando a fórmula

Answer 1

x²-3x-18=0
a=1; b=-3; c=-18
∆=b²-4ac⇒ ∆=(-3)²-4.1.(-18)⇒ Δ=9+72⇒ Δ=81
x=-b±√∆ / 2.a⇒ x=-(-3)±√81 / 2.1⇒ x=3±9 / 2
x'=3+9/2⇒ x'=12/2⇒ x'=6
x"=3-9/2⇒ x"=-6/2⇒ x"=-3
S={-3 , 6}

Answer 2

R=raiz
D=delta
RD=raiz de delta
formula de baskara er 
RD=(b)²-4ac
RD=(-3)²-4.1.18
RD=(9)+72
RD=9+72
RD=81
D=R81
D=9
OUTRA FORMULA
X¹=-b+D/2
X²=-b-D/2
X¹=-(-3)+9/2=3+9/2+12/2=6
x²=-(-3)-9/2= -6/2=-3
as raizes sa0 6 e -3