-2y + 14 = -x
-2y + x = -14
-2y = -14 – x
-2y = -x – 14
-7 – x/2 = -y
-7 + y = x/2
-7 = -y + x/2
-7 = x/2 – y
-14 – x = -2y
-14 + 2y = x
-14 = -2y + x
-14 = x – 2y

-x – 14 = -2y
-x + 2y = 14
-x = -2y + 14
-x = 14 – 2y
-x/2 – 7 = -y
-x/2 + y = 7
-x/2 = -y + 7
-x/2 = 7 – y
-y + 7 = -x/2
-y + x/2 = -7
-y = -7 -x/2
-y = -x/2 – 7

2y – 14 = x
2y – x = 14
2y = 14 + x
2y = x + 14
7 – y = -x/2
7 + x/2 = y
7 = -x/2 + y
7 = y – x/2
14 – 2y = -x
14 + x = 2y
14 = -x + 2y
14 = 2y – x

x – 2y = -14
x + 14 = 2y
x = -14 + 2y
x = 2y – 14
x/2 – y = -7
x/2 + 7 = y
x/2 = -7 + y
x/2 = y – 7
y – 7 = x/2
y – x/2 = 7
y = 7 + x/2
y = x/2 + 7