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**Anne54321****Guest**

Hi

If MARGIN+PICNUM*(MARGIN+WIDTH)+MARGIN+WIDTH=PICW/2

then WIDTH= ?

Thanks

**mathsyperson****Moderator**- Registered: 2005-06-22
- Posts: 4,900

MARGIN+PICNUM*(MARGIN+WIDTH)+MARGIN+WIDTH=PICW/2

Put the additional MARGIN+WIDTH inside the brackets by factorising:

MARGIN+(PICNUM+1)*(MARGIN+WIDTH)=PICW/2

Put the MARGIN on the right-hand side:

(PICNUM+1)*(MARGIN+WIDTH)=PICW/2-MARGIN

Divide by (PICNUM+1):

MARGIN+WIDTH=(PICW/2-MARGIN)/(PICNUM+1)

Take away MARGIN:

WIDTH=[(PICW/2-MARGIN)/(PICNUM+1)]-MARGIN

Why did the vector cross the road?

It wanted to be normal.

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**krassi_holmz****Real Member**- Registered: 2005-12-02
- Posts: 1,906

Why not

w=(pw/2-m)/(pn+1)-m

IPBLE: Increasing Performance By Lowering Expectations.

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**seerj****Member**- Registered: 2005-12-21
- Posts: 42

MARGIN+PICNUM*(MARGIN+WIDTH)+MARGIN+WIDTH=PICW/2

Let m MARGIN p PICNUM x WIDTH q PICW

Then

m+p*(m+x)+m+x=q/2

px+x=q/2 -m -pm -m

x ( p+1 )=q/2-2m-pm

x= (q-4m-2pm)/2*(p+1)

x= (q-2m*(2+p)) / (2*( p+1 ))

WIDTH=( PICW-2MARGIN*(2+PICNUM))/(2*( PICNUM+1))

*Last edited by seerj (2005-12-29 03:06:42)*

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**Anne54321****Guest**

I have tried these equations in a computer program and I don't think they're yielding the correct answers.

If you take

MARGIN+PICNUM*(MARGIN+WIDTH)+MARGIN+WIDTH=PICW/2

and then use say MARGIN=10,PICNUM=7,WIDTH=10 and use these numbers to derive PICW

and then use one of the WIDTH solution equations with these numbers inserted they don't balance up ( by my reckoning!) Am I at fault or are these solutions ( which all yield the same answers) missing something ? Is it maybe a question of operator precedence?

**krassi_holmz****Real Member**- Registered: 2005-12-02
- Posts: 1,906

IPBLE: Increasing Performance By Lowering Expectations.

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**Anne54321****Guest**

My mistake. It works perfectly. Many thanks for al your help. I've learnt a lot from you all.

**krassi_holmz****Real Member**- Registered: 2005-12-02
- Posts: 1,906

You'll learn a lot from us.

IPBLE: Increasing Performance By Lowering Expectations.

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