7X + 5Y = - 36
X = 16 - 6Y
you have been given X, so substitute it into top equation
7(16 - 6Y) + 5Y = - 35
112 - 42Y + 5Y = - 36
112 - 37Y = - 36
- 37Y = - 148
Y = 4
------now, find X ( bottom equation )
X = 16 - 6(4)
X = 16 - 24
X = - 8
------check in both equations
7(- 8) + 5(4) = - 36
- 56 + 20 = - 36
- 36 = - 36
------top checks. Now bottom
- 8 = 16 - 6(4)
- 8 = 16 - 24
- 8 = - 8
------both check in this consistent system
X = 16 - 6Y
you have been given X, so substitute it into top equation
7(16 - 6Y) + 5Y = - 35
112 - 42Y + 5Y = - 36
112 - 37Y = - 36
- 37Y = - 148
Y = 4
------now, find X ( bottom equation )
X = 16 - 6(4)
X = 16 - 24
X = - 8
------check in both equations
7(- 8) + 5(4) = - 36
- 56 + 20 = - 36
- 36 = - 36
------top checks. Now bottom
- 8 = 16 - 6(4)
- 8 = 16 - 24
- 8 = - 8
------both check in this consistent system