система 6у-5х=70 и -5х-6у=-50

Question

система 6у-5х=70 и -5х-6у=-50

Answer 1

6у-5х=70,

-5х-6у=-50

_________

-10х=20,

5х+6у=50

________

х=-2

-10+6у=50

_______

х=-2

у=10

Answer 2

   -5х+6у=70

+  

   -5х-6у=-50

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

 -10х=20

х=-2

 

у=(70+5х)/6=10