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# AS maths question - quadratics, curves, etc watch

1. Hi there, really struggling with the below, wondered if anyone has any pointers for this two-part question. It's meant to be one of the 'hard' ones at the end of a question set.

(a) Solve the equation x2-10x+9= 0

This seems fairly straightforward, it factorises (x-9),(x-1), x= 9 or 1.

(b) Hence or otherwise solve the equation 3x-2(3x-10)=-1

I badly struggled here. Presumably I need to restate the second equation so it's in a very similar form to the first one, but I drew a big blank. Being honest I'm probably a little sketchy on my rules of indices but that's not the only problem..

Obviously I'll need to get everything on one side, e.g.

1 - 3x-2(3x-10) = 0

And then i guess multiply everything by some kind of "x squared" term...

I thought about multplying everything by 32-x... giving me something like (see above for comment on rules of indices)...

32-x - 30(3x-10)=0

32-x - 3x+10=0

...

this just looks nothing like the first equation... any tips??? thanks
2. (Original post by tfpsa)
Obviously I'll need to get everything on one side, e.g.

1 - 3x-2(3x-10) = 0
Error straight away, this is not the same as what you started with.

After that just multiply by and get a familiar quadratic in
3. (Original post by RDKGames)
Error straight away, this is not the same as what you started with.

After that just multiply by and get a familiar quadratic in
hmm, brilliant, let me try that...
4. (Original post by RDKGames)
Error straight away, this is not the same as what you started with.

After that just multiply by and get a familiar quadratic in
did i really make an error there?
5. (Original post by tfpsa)
did i really make an error there?

6. (Original post by RDKGames)

duh, yep.

so i did this & then something really cack handed

multplying everything by 32-x.

32-x + 30(3x-10)=0

32-x +3x-10=0

maybe then multiply by 3x

32+(3x)2-10(3x) = 0

Let 3x = A

A2-10A+9 = 0

A = 9 or 1

so 3x = 9 or 1

x = 2 or 0???
7. (Original post by tfpsa)
...
Yep. Other than that, my suggestion to multiply by rather than would've let you arrive at the quadratic in (slightly) fewer lines.
8. (Original post by RDKGames)
Yep. Other than that, my suggestion to multiply by rather than would've let you arrive at the quadratic in (slightly) fewer lines.
great, thanks vv much. i'm not great at this stuff. you're right, 32 is quicker.

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