Question

Resolva as equações do 2°grau: URGENTE!!!

a)2x²-3x=2x+1
b)(3x+1)²+(x-2)(x+1)=-1
c)2x²-3x/2 +1/4=0
d)x+1/2 - x²+1/3=0
e)x²-1/5 = 3x-1/5

Answer 1

2x² - 3x = 2x + 1
2x² - 3x - 2x - 1 = 0
2x² - 5x - 1 = 0
delta = 25 + 8 = 33 ou +-V33
x =  ( 5 +- V33)/4 ****
b
( 3x + 1)² + ( x - 2) (x + 1) = -1
(3x)² + 2.3x.1 + 1²  ) + ( x² + x- 2x - 2 ) = -1
9x² + 6x + 1 + x²  + x² + x - 2x - 2 + 1 = 0
11x² + 4x  = 0
x( 11x + 4) = 0
x = 0 ***
11x + 4 = 0
11x = -4
x = -4/11***
c
2x²/1- 3x/2 + 1/4 = 0
mmc=  4
8x² - 6x + 1 = 0
delta = 36 - 32 = 4 ou +-V4 = +-2 ***
x = ( 6 +-2)/16
x1 =8/16 = 1/2 ***
x2 = 4/16 = 1/4 ***
d
x/1+1/2 - x²/1+ 1/3 = 0
mmc = 6
6x + 3 = 6x² + 2
6x + 3 - 6x² - 2 = 0
-6x² + 6X + 1 = 0
6X² - 6X - 1 = 0
DELTA = 36 + 24 = 60 OU +-V60
X = ( 6 +-V60)/12 ****
e
x² - 1/5 =3x - 1/5
X² - 3X - 1/5 + 1/5 = 0
X² - 3X = 0
X ( X - 3) = 0
X = 0 ***
X - 3 = 0
X = 3 ***