Question

1) resolva as equações.

a)x²-100=0
b)2 x² -50=0
c)x²-3x=0
d)2x²-8x=0
e)x²-7x+12=0
f)x²-4x+4=0
g)x²6x+25=0
h)x²+x-6=0

Answer 1

x² - 100 = 0
x² = 100
x = +-V100 = +-10 ***

2x² - 50 = 0
2x² = 50
x² = 25
x = +-V25 = +-5 ***

x² - 3x = 0
x( x - 3 ) = 0
x = 0 ****
x - 3 = 0
x = 3 ****

2x² - 8x = 0
x² - 4x = 0
x( x - 4) = 0
x = 0 ***
x - 4 = 0 
x = 4 ****

x² - 7x + 12 = 0
delta = 49 - 48 = 1 ou +-V1 = +-1 ***
x = ( 7 +-1)/2
x1 = 8/2 = 4 ***
x2 = 6/2 = 3 ***

x²- 4x + 4 = 0 ( produto notavel  )
( x - 2)² 
x - 2 = 0
x = 2 ****

x² + x - 6 = 0
delta = 1 + 24 = 25 ou +-V25 = +-5 ***
x = ( -1 +-5)/2
x1 = -6/2 = -3 ***
x2 = 4/2 = 2 ***

nota 
g falta sinal  ****