Find the value of a:
a + 3 = 5
a + 3 = 5
We only need the variable a on the left
side of this equation.
Hence we subtract 3 from both
sides.
To maintain the equality,
always do the same operation for both sides of the equation.
a + 3 – 3 = 5 – 3
a = 2
Alternatively, you can move +3 from left
side to right side. When you move +3 to right side, it becomes – 3.
a + 3 = 5
a = 5 – 3
a = 2
When you move a constant or
variable to the other side of the equation:
+ becomes –
– becomes +
x becomes ¸
¸
becomes
x
Examples
b – 6 = 10
b = 10 + 6
b
= 16
5c = 15
c = 15 ¸ 5
c
= 3
d/2 = 6
d = 6 x 2
d = 6 x 2
d
= 12
