Question

revolva as equações: a)x2-5+8=0
b) x2-x-6=0
c) x2-9=0
d) 2×2-5x=0

Answer 1

A) x²-5+8=0
X²+3=0
X²=-3
X=-√3


B) x²-x-6=0
A=1. B=-1 C=-6
∆=(-1)²-4.1.(-6)
∆=1+24
∆=25

-(-1) +-√25/2.1=
X1=1+5/2=6/2=3
1-5/2=-4/2=-2

S={-2;3}

C) x²=9
X=√9
X=3

D) 2x²-5x=0
A=2. B=-5. C=0
∆=(-5)²-4.2.0=
∆=25-0
∆=25

-(-5)+-√25÷2.2
X1=5+5/4=10/4=5/2
X2=5-5/4=0/4=0

S={5/2;0}