Expanding Brackets (Edexcel IGCSE Maths A)

Expanding a bracket means multiplying the term outside the bracket by each term inside the bracket.

So becomes from .

False.

can be thought of as .

Multiplying two negatives gives a positive, so the answer is .

You can simplify before expanding by first collecting like terms inside the brackets to give .

This can also be written as .

To simplify expressions like you expand the brackets then collect like terms.

So expands to give .
The terms are then collected to give .

False.

You cannot cancel the 3's because is an expression, not an equation.

You can only cancel both sides by 3 if you had an equation, like .

The highest power of will come from multiplying the outside term by the inside term with the highest power.

The highest power of in is .

This can be found by multiplying outside the bracket by the highest power, , from inside the bracket.

When expanding double brackets, e.g. , the acronym FOIL is used to identify which terms should be multiplied together.

• F = First (the first term from each bracket, e.g. )

• O = Outside (the outer term from each bracket, e.g. )

• I = Inside (the inner term from each bracket, e.g. )

• L = Last (the last term from each bracket, e.g. )

True.

When expanding double brackets like , every term in the left bracket gets multiplied by every term in the right bracket.

E.g. .

The next correct step is to simplify the expression by collecting like terms.

So becomes .

You cannot simplify it any further.

True.

When expanding double brackets using the acronym FOIL, is it ok to rearrange the order, such as LIFO.

When you collect terms at the end, you will have an expression that is mathematically the same as using FOIL.