Розв'язать рівняння

Question

Розв'язать рівняння

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Answer 1

x^2 - 2x - 3 = 0
D = b^2 - 4ac = 4 - 4*(-3) = 16
x1 = (2+4)/2 = 3
x2 = (2-4)/2 = -1
x^2 - 2x - 3 = (x + 1)*(x - 3) = 0

x не равно +-3

Ответ: -1.

Answer 2

ОДЗ: x≠3; x≠-3

(x+1)/(x-3) + (x-1)/(x+3) = (4x+12)/(x^2 -9) <=>

(x+1)(x+3) + (x-1)(x-3) - 4(x+3) =0 <=>

(x+1-4)(x+3) + (x-1)(x-3) =0 <=>

(x-3)(x+3) + (x-1)(x-3) =0 <=>

(x-3)(x+3+x-1) =0 <=>

(x-3)(2x+2) =0 <=>

2(x-3)(x+1) =0 <=>

x=-1