If you are given an algebraic formula and asked to make one variable the subject – e.g. make ‘x’ the subject – then you are asked to rewrite the formula so that one side has the variable and the other side has all of the other terms.

Here are a few examples ranging from simple to more complex ones.

**Example 1** – Simple case of making x the subject

**Example 2** – Expand brackets before changing the subject of the formula

**Example 3** – Variable is in both sides of the formula

**Example 4** – Variable is in the denominator

**Example 5** – Variable is in both the numerator and the denominator