2x^2+5x=0 solve by factorisation

It has to be exactly as I gave it in post 63

No problem

Do you want to try another?

No it isn't.

It is very very rare that someone will actually do this. Instead, they skip steps thinking they understand them, and have no idea how to do it themselves.

Mathematics is about more than calculations.

Well, I have two mathematics degrees (BSc/MSc) and a computing MSc, plus I've supervised maths undergraduates.

Not to mention that I'm the moderator for this forum, and the forum Guide to Posting says that you should avoid posting full solutions where possible.

Please obey the forum guidelines in future, or your posts may be removed and you may receive warning points.

Fair enough but that's how my uni teaches you.

Feeds you with samples, analyse them and expects you to come up with your own problems and then explain how you got there in depth. You are then graded on your understanding of every minute detail.

I am now a much much better mathematician than before and more confident because of this way of doing things. Like i said, if someone doesn't put in the effort themselves then they're going to get nowhere in any walk of life, not just maths.


It's a very good way of learning on computational mathematics so I see no reason why it can't be applied to just strictly math.

I didn't know you weren't allowed to give full solutions for people to learn from but it's the best method hence why in top math unis they make people get up in class and
show the other students a problem and how they solved it.

THE exam is non calculator. so the answer can be 24/4 or cant i simplify that like i said and have x= -4+or- square root of 6? or does it have to be square root of 24/4

It's a very good way of learning on computational mathematics so I see no reason why it can't be applied to just strictly math.

I didn't know you weren't allowed to give full solutions for people to learn from but it's the best method hence why in top math unis they make people get up in class and show the other students a problem and how they solved it.

It just does not work like that.

If you divide the square root of 24 by 4, you DO NOT get the square root of 6. Try not to make this mistake.

If you wish to simply $\frac {\sqrt {24}}{4}$, you can do it this way:


$\frac {\sqrt {24}}{4} = \frac {\sqrt {24}}{\sqrt {16}} = \sqrt {\frac {24}{16}}[br]\sqrt {\frac {24}{16}} = \sqrt {1.5}$

So you can have your final answer as $\sqrt {1.5} + 1$ or $\sqrt {1.5} - 1$.

It just does not work like that.

If you divide the square root of 24 by 4, you DO NOT get the square root of 6. Try not to make this mistake.

If you wish to simply $\frac {\sqrt {24}}{4}$, you can do it this way:


$\frac {\sqrt {24}}{4} = \frac {\sqrt {24}}{\sqrt {16}} = \sqrt {\frac {24}{16}}[br]\sqrt {\frac {24}{16}} = \sqrt {1.5}$

So you can have your final answer as $\sqrt {1.5} + 1$ or $\sqrt {1.5} - 1$.

....

Certainly not how they do things in Cambridge. Maybe that's not a top maths uni or something...

x(2x+5)=0
x= 0
or 2x=5, thus x=2.5

ProTip: read the entire thread before posting.

You may note that a forum environment is very different from a university one. Search some threads on TSR (and read the Guide and the threads it links to) and see for yourself. The recent thread where someone posted a full solution, the OP said "great, I really understand it now", and then had absolutely no clue how to answer a very similar question was a particular classic.

In any event, as the guide says, the vast majority of forumites studying maths at degree level agree that you learn better if you're helped towards finding your own solution, rather than just reading a full solution.

(If you already have a full solution, you may well benefit from seeing other approaches to the problem, but this is somewhat different).

I'll also note that if someone else is trying to lead someone towards a solution step-by-step, it's blatantly rude to jump in and post a full solution. Again, this is specifically mentioned in the guide to posting.

Certainly not how they do things in Cambridge. Maybe that's not a top maths uni or something...

Its how they do things in Harvard and Harvard has led to more prolific scientists and mathematicians as well as many more successful Forbes rich list members. Having attended a summer school seminar on CS50 I know.

They draw up the whole solution and decipher and talk you through it. As you can't do that online then its up to the person on the other end who wants to learn to analyse and break it down.

But we are not talking about an undergraduate course ... We are talking about someone who is trying to come to terms with gcse level maths

As I've said, it's also not how people are taught at Cambridge (undergraduate). Although what he's actually saying seems quite confused anyhow.

In any event, TSR is not a university. If you want someone to demonstrate a solution for you, a school or university is the appropriate place. Not here.