After having worked through the previous sections, you should now be familiar with the idea of using an equation to represent a relationship between two or more variables.
We have considered both arithmetic equations (involving only numbers) and algebraic equations (involving letters as well).
We can use equations to find the value of one variable, given the value(s) of one or more other variables.
We can rearrange or manipulate an equation to make any one of the variables the "subject" of the equation, so that we can determine the value of whichever variable it is that we don't know.
To carry out this rearrangement, we can add, subtract, multiply or divide, but we must do the same thing to both sides of the equation.
We use brackets when we will carry out more than one operation, to show which must be carried out first. The operation in brackets must always be done first.
To become used to manipulating equations and hence solving them, you need lots of practice. You can get this from the Exit Quiz.