What is -6x + y =5 x + 3y = -23?

-6x + y =5    re-arrange as    y = 5 + 6x   and sub in to the next equation

 

x + 3y = -23

x + 3 (5+6x) = -23

x + 15 + 18x = -23

19x + 15 = -23

19x = -38

x = -2                            Now sub this value in to one of the equations (I'll us th ered one) to find the y value(s)

                y = 5 + 6x

                y = 5 + 6(-2)

                y = 5-12

                y = -7