A level maths (writing answers)

Hey everyone
In maths A level does it matter to how you write an equation/expression answer to a question? An example is in the book, its answer is 10t-2r but I wrote -2r + 10t. I know this may sound like a silly question but would I still get the marks? I know in maths, there's an order to writing things especially with expressions and terms etc.

Hey everyone
In maths A level does it matter to how you write an equation/expression answer to a question? An example is in the book, its answer is 10t-2r but I wrote -2r + 10t. I know this may sound like a silly question but would I still get the marks? I know in maths, there's an order to writing things especially with expressions and terms etc.

I believe you would get marks for writing it like that in the situation you've described.

However, if it asks for a particular form (eg kroot3 or 'in its simplest form' then you might not get it. (Neither of those things apply to the example you've given).

In mark schemes you may see 'o.e' which is or equivalent, in which case anything that is 'the same' as the answer given is okay.

Oh cool. Thanks. It's just last time my tutor had said something about order. Something about x^2 is always written before x and 2x. I still don't understand what he had meant but as long as it's the same answer, I'm happy.

Oh, I'm not so sure then. It's probably good practice to write answers in descending powers of x. I'd give you the marks myself regardless but I am not an examiner. Maybe someone's who's 100% sure can let us know.

Thanks for your help though, really appreciate it. Wanted to ask, do you know how to solve (r^2 + 3t^2 + 9) - (2r^2 + 3t^2 -4) ?

Oh cool. Thanks. It's just last time my tutor had said something about order. Something about x^2 is always written before x and 2x. I still don't understand what he had meant but as long as it's the same answer, I'm happy.

Thanks for your help though, really appreciate it. Wanted to ask, do you know how to solve (r^2 + 3t^2 + 9) - (2r^2 + 3t^2 -4) ?

Thanks guys, appreciate your help x

I would agree with all the comments about expressions being mathematically equivalent. However, in maths exams sometimes the question will want the answers "In the form" for example " ... equation in the form ax + by + c = 0 where a, b, and c are integers" or "in the form a + bc where a, b ,c are rational numbers" or " .. to two decimal places" and you will lose a mark if you do not honour that requirement even if your answer is equivalent to the correct answer. I am guessing the teacher who asks / requires for polynomials to be written in descending powers sometimes sees solutions to quadratics performed incorrectly because the values for a, b and c are incorrectly substituted in the quadratic discriminant. Conversely many textbooks write polynomials starting with the constant term in the form of ascending powers $a_0 + a_1x + a_2x^2 + .. + a_nx^n$. Aesthetically I prefer this latter form but I can't explain why.

Clive

If it asks for an anwer in the fom of ax +by + c , I doubt yu'd lose a mark for giving your answer as by + ax+ c = 0 and so on.

I hesitate to use the word "obviously", but, obviously. My point still stands. Read the mark scheme.

The order in which you write things is has no effect on mathematical validity and will subsequently not affect your marks one iota.
$2x^2 - 2x - 2$
$-2x + 2x^2 - 2$
$-2 - 2x + 2x^2$
$2x^2 - 2 - 2x$
are all equivalent and writing down any one of them will get you your marks.

Unless it requires it in standard: $ax^2 + bx + c$ form.

Nah, I would think that form means that you can't leave your answers as $\frac{1}{2}ax^2 + (b-1)x + c-1 + 1 + x + \frac{1}{2}ax^2$, you'd get your marks for writing it down as $c + bx + ax^2$ (which is actually a form used quite a lot in uni-level textbooks)

Nope, A Level mark schemes are so picky for edexcel on that.