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@ @QRU@                     @pý†bɾa@                 @

                 x2 + ax + 1 = x 2 − x − a
             ax + x + a + 1 = 0
         x(a + 1) + (a + 1) = 0

              (x + 1)(a + 1) = 0

                               .a = −1 x = −1
                  . x 2 − x + 1 = 0 a = −1

             . ∆ = 1 − 4 = −3 < 0

                                              x = −1

         .a = x2 − x = (−1)2 − (−1) = 2

         x 2 + 2x + 1 = 0
              (x + 1)2 = 0
                      x = −1

         x2 −x −2 = 0
         (x − 2)(x + 1) = 0

         x =2       x = −1

               .x = −1
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