Chapter 9: Algebraic expressions and expanding brackets
You need to be able to work with algebraic expressions confidently
You can use the index laws to simplify algebraic expressions
You can square or cube a whole expression
Remember that if a letter appears on its own then it has the power 1
Algebraic expressions may also contain negative and fractional indices
When you are multiplying expressions:
Multiply any number parts first
Add the powers of each letter to work out the new power
When you are dividing expressions:
Divide any number parts first
Subtract the powers of each letter to work out the new power
Start by simplifying the top part of the fraction
Do the number part first then the powers
Next divide the expressions
Divide the number part, then divide the indices
Expanding or multiplying out brackets is a key algebra skill
You have to multiply the expression outside the bracket by everything inside the bracket
‘Expand and simplify’ means multiply out and then collect like terms
When you expand, you need to be careful with negative signs in front of the bracket
Negative signs belong to the term to their right
Multiply out the brackets first and then collect like terms if possible
You can use the grid method to expand two brackets
Or you can use the acronym FOIL to expand two brackets
Remembered as smiley face
First, outer, inner, last terms
If you have to multiply three factors, don’t try to do it all in one step
Expand and write brackets around the whole expansion
Then multiply every terms inside the brackets by x
You need to be able to work with algebraic expressions confidently
You can use the index laws to simplify algebraic expressions
You can square or cube a whole expression
Remember that if a letter appears on its own then it has the power 1
Algebraic expressions may also contain negative and fractional indices
When you are multiplying expressions:
Multiply any number parts first
Add the powers of each letter to work out the new power
When you are dividing expressions:
Divide any number parts first
Subtract the powers of each letter to work out the new power
Start by simplifying the top part of the fraction
Do the number part first then the powers
Next divide the expressions
Divide the number part, then divide the indices
Expanding or multiplying out brackets is a key algebra skill
You have to multiply the expression outside the bracket by everything inside the bracket
‘Expand and simplify’ means multiply out and then collect like terms
When you expand, you need to be careful with negative signs in front of the bracket
Negative signs belong to the term to their right
Multiply out the brackets first and then collect like terms if possible
You can use the grid method to expand two brackets
Or you can use the acronym FOIL to expand two brackets
Remembered as smiley face
First, outer, inner, last terms
If you have to multiply three factors, don’t try to do it all in one step
Expand and write brackets around the whole expansion
Then multiply every terms inside the brackets by x