An equation is like a weighing scale - both sides should always be perfectly balanced. To solve the equation you need to find the value of missing numbers and perform the same operation to each side.

Example 1

For example, suppose you are trying to find out how many sweets are in the bag shown here.

By subtracting three sweets from each side, the scales remain balanced.

You can now see that one bag is equivalent to two sweets. Written algebraically, this is:

x + 3 = 5
Subtract 3 from both sides, to give:
x = 2

Example 2

In this case, two bags of sweets are equivalent to six sweets:

To find the equivalent of one bag, divide both sides in half:

Written algebraically, this is:

2x = 6
Divide both sides by 2, to give:
x = 3

Check your answers

For example, if you think that the answer to the equation 'x + 5 = 12' is x = 7, then to check it replace x with 7.

7 + 5 does equal 12, so your answer is correct.