Respuesta :

choixongdong
8x + 7y = -15 (1st)
-7x - 9y = -7 (2nd)

multiply (1st) by 7 and (2nd) by 8

56x + 49y = -105 (multiply 7)
-56x - 72y = -56 (multiply  8)
--------------------------------------------add
         -23y = -161
               y = 7

8x + 7y = -15
8x + 7(7) = -15
8x + 49 = -15
8x = -64
x = -8

answer
x = -8 and y = 7

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