Simultaneous equations

Original post by Lucofthewoods

Done this with these workings- answer book says it's wrong. Can you explain what I need to do?

is this aqa lvl 2 further maths?

Reply 4

Original post by Lucofthewoods

Done this with these workings- answer book says it's wrong. Can you explain what I need to do?

Ignore the other posts, your exapansions are correct. You've simply used the quadratic formula wrong, you should get:

\displaystyle x = \frac{-8 \pm \sqrt{8^2 - (4 \times 5 \times -13}}{2\times 5}

Check up on the quadratic formula and see the form!

Original post by Mayhem™

where did you get +4x and +4x from? the x^2 you have outside the bracket shouldn't be used to expand
also, you haven't actually supplied the question with an answer...

+4x + 4x comes from expanding the square, no?

Original post by maggiehodgson

Compare the fist line of your expansion with the second. I think you've written it down incorrectly.

Looks correct to me.

Reply 5

Original post by danr2

are you doing further maths lvl 2?

Original post by danr2

is this aqa lvl 2 further maths?

Don't hijack other threads, wait for someone to reply to the one you've created.

Reply 6

Mayhem™

19

Original post by Zacken

+4x + 4x comes from expanding the square, no?

I have no idea what I was thinking :doh:

Reply 7

DylanJ42

18

Original post by Lucofthewoods

Done this with these workings- answer book says it's wrong. Can you explain what I need to do?

5x^2 + 8x - 13= 0

Split the x term into;

5x^2 -5x +13x -13 = 0

and you don't need the quadratic formula at all

Reply 8

Original post by Zacken

Don't hijack other threads, wait for someone to reply to the one you've created.

wtf dude? if no one is answering , what do you expect me to do? sit on my ass and wait till the exam day?

Reply 9

maggiehodgson

14

Original post by Zacken

Ignore the other posts, your exapansions are correct. You've simply used the quadratic formula wrong, you should get:

\displaystyle x = \frac{-8 \pm \sqrt{8^2 - (4 \times 5 \times -13}}{2\times 5}

Check up on the quadratic formula and see the form!

+4x + 4x comes from expanding the square, no?

Looks correct to me.

Oh dear. (2x +2)(2x+2) = as per 1st line but then, sideways on, it looks like 4x^2 has turned into 8x^2.

Sorry folks

Reply 10

Original post by danr2

wtf dude? if no one is answering , what do you expect me to do? sit on my ass and wait till the exam day?

Yes.

Edit to add: 'no one is answering' it's barely been 15 minutes, have some patience. Stop feeling so self-entitled.

Reply 11

Original post by Lucofthewoods

Done this with these workings- answer book says it's wrong. Can you explain what I need to do?

i think you should use the substitution method

Reply 12

Original post by danr2

i think you should use the substitution method

That is precisely what he's done, have you even bothered looking at his solution?

Reply 13

Original post by Zacken

That is precisely what he's done, have you even bothered looking at his solution?

Original post by Zacken

Yes.

Edit to add: 'no one is answering' it's barely been 15 minutes, have some patience. Stop feeling so self-entitled.

patience? patience doesn't apply do this situation. maybe they have the best answers to my question but they probably won't see it if i don't ask them, have you thought about that?
anyway don't reply to my post anymore if you haven't got any relevant question to answer.

Reply 14

Original post by danr2

patience? patience doesn't apply do this situation. maybe they have the best answers to my question but they probably won't see it if i don't ask them, have you thought about that?
anyway don't reply to my post anymore if you haven't got any relevant question to answer.

Your posts will all be deleted because they're irrelevant trash. I haven't thought about that, you know why? Because it's nonsense. I love how you're going on about relevance and yet you're trying to "help" a person by telling him to do what he's already done.

Reply 15

username738914

21

Original post by danr2

patience? patience doesn't apply do this situation. maybe they have the best answers to my question but they probably won't see it if i don't ask them, have you thought about that?
anyway don't reply to my post anymore if you haven't got any relevant question to answer.

Mate just make a new thread with your questions. Don't clog up other people's threads.

Posted from TSR Mobile

Reply 16

Original post by Princepieman

Mate just make a new thread with your questions. Don't clog up other people's threads.

Posted from TSR Mobile

Thing is, he did make a thread before posting the question in everybody elses thread (in the wrong forum as well :lol:

).

Reply 17

Original post by Princepieman

Mate just make a new thread with your questions. Don't clog up other people's threads.

Posted from TSR Mobile

Fine, I will but next time learn how to tell someone to do something because that is a bad approach to correct someone if you really want them to do as you said.

(edited 8 years ago)

Reply 18

Original post by Zacken

Thing is, he did make a thread before posting the question in everybody elses thread (in the wrong forum as well :lol:

).

where did i post the question in everybody elses thread? look, don't say something you haven't seen. i was gonna ask him how hard it was which was not included in my thread. 'is this aqa lvl 2 f.maths'? had nothing got to do with my thread
besides that there's nothing wrong and it wasn't even my intention to 'hijack' his thread so don't say something you don't know about.
if i posted it in the wrong forum, what is wrong? don't we all make mistakes in life? you think you are all that but actually you are not. you probably have the book knowledge but do you have some common sense, do you even think twice before you let something come out of your mouth? i guess not cuz if you did you wouldn't be that stupid to come up with something you haven't seen.
if i had seen he used the substitution method, i wouldn't have told him that. hasn't something like that ever happened to you where the person told you that is exactly what they did or had done? i don't blame you for this anyway.

hope you don't get into Cambridge with your immature brain if you don't change from now.

(edited 8 years ago)

Reply 19