Question

Equacao de 2 grau
a) 2x²= x+3
b) (x+1) . (x-1)= 6 (x-1)
c) x(x-2)+1=2(x+3)
d) x(x-3)=28
e) 3(x-7)= -x (x+1)
Aguem me ajude pfv me passe tudinho as respostas pfv Obg

Answer 1

a)2x²-3-x=0
2x²-x-3=0

Δ=b²-4.a.c

Δ=-1²-4.2.-3
Δ=1+24
Δ=25

$\frac{-b+- \sqrt{belga} }{2.a}$

$\frac{+1+-5}{4}$
x'=$\frac{1+5}{4} = \frac{6/2}{4/2}= \frac{3}{2}$
x''=$\frac{1-5}{4} = \frac{-4}{4} =-1$

b)x²-x+x-1=6x-6
x²-x+x-6x+6=0
x²-6x+6=0

Δ=-6²-4.1.6
Δ=36-24
Δ=12

nao tem raiz.

c)x²-2x+1=2x+6
x²-2x+1-2x-6=0
x²-4x-5=0

Δ=-4²-4.1.-5
Δ=16+20
Δ=36

$\frac{4+-6}{2}$
 
x'=$\frac{4+6}{2} = \frac{10}{2} =5$

x''=$\frac{4-6}{2} = \frac{-2}{2} =-1$

d)x²-3x-28=0

Δ=-3²-4.1.-28
Δ=9+42
Δ=51 nao tem raiz.

e)3x-21+x²-x=0
x²+2x-21=0

Δ=2²-4.1.-21
Δ=4+84
Δ=88 nao tem raiz.