Uhh... algebra... (1 Viewer)

[kazemagic]

Well since this question was listed in camb 3u yr 11 textbook, i'll just ask my question here. Sorry if wrong section.
How do u factorise these 2 equations O_O

Sankyu

 

[RealiseNothing]

There's two ways, but this is the way I do it.



We can see that this is somewhat similar to:



Here and

So if we want to put it into the form of we need to find the square root of and

This gives us:



However if we expand this we get:



This is the same as the original expression except we have an extra

So we just minus it, hence.



Notice this is now a difference of two squares, so let's do that:



We can do the same sort of method again here, by inspection we notice what the square roots are, and how it compares to a standard expression:



And that is fully factorised, if you were doing 4U we could go further and use the sum of two squares, but for 3U just leave it here.

 

[nightweaver066]

Hints for both:
Perfect square
0 = a - a

 

[kazemagic]

So we add something then minus something to do this question right?

 

[nightweaver066]

So we add something then minus something to do this question right?

Give it a shot and post back how it goes

 

[kazemagic]

kk got the first question thx now doing 2nd one

 

[kazemagic]

Dw... got them lol, thx weaver and nothing

 

[karnbmx]

Both questions require this relationship:

(a + b)^2 = a^2 + 2ab +b^2

figure out how to manipulate each one into this form, and work from there....