Question

-1/3 + 4/x+1 = 7/x²-1

Answer 1

Resposta:

Explicação passo-a-passo:

-1/3 + 4/x+1 = 7/x²-1

X diferente de 1

X diferente de - 1

Mmc = 3.(x+1).(x-1)

[- 1.(x+1).(x-1) + 4.3.(x-1) = 3.7/3(x+1).(x-1)

-----------------------------

3(x+1).(x-1)

- (x^2 - 1) + 12.(x-1)= 21

- (x^2 - 1) + 12x - 12 = 21

- x^2 + 1 + 12x - 12 - 21 = 0

- x^2 + 12x - 32 = 0 (-1)

X^2 - 12x + 32 = 0

a = 1; b = - 12; c = 32

/\= b^2 - 4ac

/\= (-12)^2 - 4.1.32

/\= 144 - 128

/\= 16

\/ /\= \/16 = 4

X = [ - b +/- \/ /\] / 2a

X = [- (-12) +/- 4]/2.1

X ' = (12+4)/2 = 16/2 = 8

X " = (12-4)/2 = 8/2 = 4

R.: {4,8}