Calculation with an variablePerfect square trinomials are formulas which enable us to go faster when making calculation with a variable x.
Before reading this page, you should master the algebra part in the 7th Grade lesson and know how to do again the examples of the web site.
You know how to develop these expressions :
The author (who is nice) hopes that you know your multiplication tables well. If youíre still using your calculator to make 7 times 8, it is really urgent to learn your tables before you go on. You CANíT go on reading this web site if you still need more than 25 seconds in the test in the chapter 'equations' in the 7th Grade syllabus.
If you develop , logically you have : , so :
Perfect square trinomialsThe first perfect square trinomial enables to suppress the intermediate steps. Indeed, in general :
The equivalence is the first perfect square trinomials.
You also have : .
The equivalence is the second perfect square trinomials.
Finally : .
The equivalence is the third perfect square trinomials.
Using the perfect square trinomialsHere are some examples in which you can use them :
A few other examples a little longer :
Maths are just like tennis : to get it, you must train a lot. If you have understood the examples mentioned above (which is good), you must train and make others.
See also : algebra on fmaths.com