Question

Resolva as seguintes equações do 2° Grau.


A) 3x²-12y+4= 0

B) 9y²-12y+4= 0



Socorro Please *Urgente*

Answer 1

A) 3x²-7x+4=0

a=3 b=-7 c=4

∆=b²-4.a.c

∆=(-7)²-4.3.4

∆=49-48

∆=1

x=-b±√∆/2.a

x=-(-7)±√1/2.3

x¹=7+1/6=8/6=4/3

x²=7-1/6=6/6=1

S={1,4/3}

B) 9y²-12y+4=0

a=9 b=-12 c=4

∆=(-12)²-4.9.4

∆=144-144

∆=0

x=-(-12)±√0/2.9

x¹=12+0/18=12/18=2/3

x²=12-0/18=12/18=2/3

S={2/3}

Espero ter ajudado

Answer 2

Oie, Td Bom?!

A)

$3x {}^{2} - 7x + 4 = 0$

$3x {}^{2} - 3x - 4x + 4 = 0$

$3x \: . \: (x - 1) - 4(x - 1) = 0$

$(x - 1) \: . \: (3x - 4) = 0$

• $x - 1 = 0⇒x = 1$

• $3x - 4 = 0⇒x = \frac{4}{3}$

$S = \left \{ 1 \: , \: \frac{4}{3} \right \}$

B)

$9y {}^{2} - 12y + 4 = 0$

$3 {}^{2} y {}^{2} - 2 \: . \: 3y \: . \: 2 + 2 {}^{2} = 0$

$(3y) {}^{2} - 2 \: . \: 3y \: . \: 2 + 2 {}^{2} = 0$

$(3y - 2) {}^{2} = 0$

$3y - 2 = 0$

$3y = 2$

$y = \frac{2}{3}$

$S = \left \{ \frac{2}{3} \right \}$

Att. Makaveli1996