Factorising
Factorising
Factorising is the opposite of expanding brackets
You need to look for the largest factors you can take out of every term in the expression
Factorising x^2 + bx + c
You need to write the expression with two brackets
x^2 + 7x + 10
You need to find two numbers which add up to 7 and multiply to make 10
5+2=7
5x2=10
When factorising x^2 + bx + x use this table to help find the two numbers
b | c | Factors |
---|---|---|
Positive | Positive | Both numbers positive |
Positive | Negative | Bigger number positive and smaller number negative |
Negative | Negative | Bigger number negative and smaller number positive |
Negative | Positive | Both numbers negative |
Factorising ax^2 + bx + x
One of the brackets must contain a ax term
Try pairs of numbers which have a product of c
Check each pair by multiplying out the brackets
Difference of two squares
You can factorise expression that are written as something^2 - something else^2
Factorising
Factorising
Factorising is the opposite of expanding brackets
You need to look for the largest factors you can take out of every term in the expression
Factorising x^2 + bx + c
You need to write the expression with two brackets
x^2 + 7x + 10
You need to find two numbers which add up to 7 and multiply to make 10
5+2=7
5x2=10
When factorising x^2 + bx + x use this table to help find the two numbers
b | c | Factors |
---|---|---|
Positive | Positive | Both numbers positive |
Positive | Negative | Bigger number positive and smaller number negative |
Negative | Negative | Bigger number negative and smaller number positive |
Negative | Positive | Both numbers negative |
Factorising ax^2 + bx + x
One of the brackets must contain a ax term
Try pairs of numbers which have a product of c
Check each pair by multiplying out the brackets
Difference of two squares
You can factorise expression that are written as something^2 - something else^2