Simplifying expressions
Tidying an expression by adding or subtracting 'like terms', which are terms with exactly the same letter part.
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Analogy
Like sorting a bag of sweets: you can add the reds together, but not the reds and blues.
Example
3x + 2y + 5x - y= 3x + 5x + 2y - y= 8x + y
In practice
A shopping total of 3 apples + 2 pears + 5 apples - 1 pear becomes 8 apples + 1 pear.
Practice
Flashcards
- Simplify 3x + 2y + 5x - y.8x + y. Collect the x terms and the y terms separately.
Questions people ask
What are like terms in algebra?
Like terms have the same letters raised to the same powers, so only the numbers in front differ. 3x and 5x are like terms. 3x and 3x^2 are not, because the powers are different. Only like terms can be added or subtracted.
Can you add x and x^2?
No. They are different kinds of term, like metres and square metres. x + x^2 cannot be simplified and stays as it is. If x = 3 you could work out 3 + 9 = 12, but the expression itself does not combine.