Question

Resolva as equaçoes de 2º GRAU:
3x²-7x+2=0

Outra:
4x²+9=12x

Outra:
x²=x+12

Answer 1

3x^2-7x+2=0
delta=b^2-4ac
delta=(-7)^2-4.3.2
delta=49-24
delta=25
x=-b-/+ raiz de delta/2a
x=-(-7)-5/2.3
x=7-5/6
x=2/6 (:2)
x=1/3
x=-(-7)+5/2.3
x=7+5/6
x=12/6
x=2
4x^2+9=12x
4x^2-12x+9=0
delta=b^2-4ac
delta=(-12)^2-4.4.9
delta=144-144
delta=0
x=-b-/+ raiz de delta/2a
x=-(-12)-0/2.4
x=12-0/8
x=12/8 (:4)
x=3/2
x^2=x+12
x^2-x-12=0
delta=b^2-4ac
delta=(-1)^2-4.1.(-12)
delta=1+48
delta=49
x=-b-/+ raiz de delta/2a
x=-(-1)-7/2.1
x=1-7/2
x=-6/2
x=-3
x=-(-1)+7/2.1
x=1+7/2
x=8/2
x=4

Answer 2

Usa o Delta
Delta: b^-4.a.c
Delta: ( 7 ) ^ - 4.3.2
Delta: 49 - 24
Delta: 25
Raiz quadrada de 25 é ( 5 )