x - 7y = -11      (1)
    5x + 2y = -18      (2)


From equation (1),  express  x = 7y - 11  and substitute it into equation (2). You will get

    5*(7y - 11) + 2y = -18.


Thus you have an equation for one single unknown y.   Simplify it and find y


    35y - 55 + 2y = -18

    35y + 2y = 55 - 18

        37y  =    37.

          y  =     = 1.


Now substitute this value of y into equation (1) to get


    x - 7*1 = -11,

    x       = -11 + 7 = -4.


Answer.  The solution is  x= -4;  y= 1.


    Check the solution on your own by substituting the found values into the original equations.