<PRE><B>Question 21506</B>
The objective of these kind of problems is to seperate the variable y. We do this by performing various mathematical operations that put the variable on 1 side and the numbers on the other side.

11-y = 4
Adding y on both sides
11 -y +y = 4+y
11 = 4+y
Subtracting 4 on both sides
11-4 = 4+y-4
7=y
or y = 7. 

Similarly for the second problem
-2+y=-12
Adding 2 on both sides
-2+y +2 = -12+2
y = -10.</PRE>