Which of the following is an example of a linear system of equations?


5
x
2
+
6
y
=
13


6
x
−
12
y
=
14


5
x
+
6
y
=
13


6
x
−
12
y
2
=
14


5
x
+
6
y
=
13


6
x
2
−
12
y
=
14


5
x
+
6
y
=
13