The 4th term in the expansion of (3y-2x)^5, when written in decending powers of y?

You can work it out from the following:

Alan, I strong suspect that this was supposed to be done without a calculator!

Although, since the Sportslover gave you a thumbs up, maybe I am wrong.

it was a multiple choice question melody :)

weren't you supposed to be able to do it without a calculator?

probably , but im not sure how to

That is what I am saying.  you should ask people to explain.  And give thumbs up when you are totally satisfied that you have been taught or at lest told what you need to know.

would you like me to try and explain or are you happy with just the answer?

I would love for you to explain it thanks !

$$(3y-2x)^5$$

the highestr power of y is going to be 5 followed by 4,3,2,1,0

The forth largest is the power of 2 so you need the term with y² in it.  Which will be

$$(3y)^2...$$

The whole term will be

 $$5C2\times (3y)^2 \times (-2x)^3 = 10\times9y^2\times -8x^3 = -720x^3y^2$$

Now if you don't understand, tell me what is troubling you and I will attempt to explain better!

no that totally helps thanks !

You are very welcome.

I see you only joined yesterday.

Welcome to Web2.0calc forum.  I hope that you learn lots and have fun here.

haha ya thanks ! i hope so to ! I have a diploma june 24th

do you have to pass a supervise test for that?

Are you getting us to do all your homework for you?

You have a lot of questions up here.

yea its a supervised exam haha no im done all my course work these are just types of questions they didnt cover very well so i wanna see how others do it os see if they have tricks :)

okay then.