SOLUTION: Solve for (x,y) in the system of equations 2x + y = -7 x = 2y - 11 - 5x + 16y

Simplify second equation by combining the common terms

    x + 5x = 2y - 11 + 16y.

    6x = 18y - 11.    (*)


Now express  y = -7 - 2x  from the first equation and substitute it into (*).
You will get

    6x = 18*(-7-2x) - 11,

    6x = -126 - 36x - 11,

    6x + 36x = -126 - 11,

       42x   = -137,

         x   = .


From here,  y = -7 - 2x = -7 -  = -7 +  = .