Question

reaolva as equaçoes
a)(x-4)^2=5X+16
b)x^2-9x=0
c)21x^2+7x=0
d)6x^2-x=0
e)5x(x-1)+(x+4)^2=16+6x

^2 esse simbolo significa elevado ao quadrado ta

please me ajudem

Answer 1

a)(x-4)²=5X+16
(x - 4).(x - 4) = 5x + 16
x² - 4x - 4x  + 16 = 5x + 16
x² - 4x - 4x - 5x + 16 - 16 = 0         elimina  + 16  e  - 16
x² - 13x = 0 
x.(x - 13)
x = 0

(x - 13) = 0
x - 13 = 0
x = + 13

S[0 , 13]


b)x²-9x=0
x.(x - 9) = 0
x = 0

(x - 9) = 0
x - 9 = 0
x = + 9

S[0 , 9]


c)21x²+7x=0   ÷(7)
3x² + x = 0
x.(3x + 1) = 0
x = 0

(3x + 1) = 0
3x + 1 = 0
3x = - 1
x = - 1/3

S[0 , - 1/3]



d)6x² - x=0
x.(6x - 1) = 0
x = 0

(6x - 1) = 0
6x - 1 = 0
6x = + 1
x = 1/6

S[0 , 1/6]



e)5x(x-1)+(x+4)²=16+6x
5x² - 5x + (x+4).(x+4) = 16 + 6x
5x² - 5x + (x² + 4x + 4x + 16) = 16 + 6x
5x² - 5x + (x² + 8x + 16) = 16 + 6x
5x² - 5x + x² + 8x + 16 = 16 + 6x
5x² + x² - 5x - 6x + 8x + 16 - 16 = 0       elimina + 16 - 16
6x² - 11x + 8x = 0
6x² - 3x = 0  ÷ (3)
2x² - x = 0
x.(2x - 1) = 0
x = 0

(2x - 1) = 0
2x - 1 = 0
2x = + 1
x = 1/2     ou 0,5

S[0 , 1/2  ou  0,5]