помогите с уравнениями плизз=(​

a) (x-1)/2 = 4/(х +1)

(x-1)(x+1) = 2*4

x^2+1 = 8

x^2 = 7

x = √7

х = -√7

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б) (х+2)/2 = 6/(х-2)

(х-2)(х+2) = 6*2

х^2+4 = 12

х^2 = 8

х= √8 = 2√2

х= -2√2

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в) (х+3)/2 = (3х+9)/(х+3)

(х+3)^2 = 6х+18

х^2 + 6x + 9 - 6х - 18 = 0

х^2 - 9 = 0

(х-3)(х+3) = 0

х = 3

х = -3

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г) 7/(х-7) = (х+7)(х-7)

7х-49 = х^2-49

7х-х^2 = 0

х(7-х) = 0

х = 0

х = 7

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