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# Unable to solve these equations.. watch

1. OK, this has took up most of my evening as I can't see where I'm going wrong. I'm able to solve for B1 and C1, but then when trying to solve equations 3 and 4 I am continually coming up with answers that actually only satisfy equation 3??

I'll start from the beginning as B1 and C1 are irrational and the numbers worked with are quite small.

1)

2)

Which are solved [by solving for C1 in (2) and subbing into (1)] to give:

B1 = 0.005308...
C1 = 0.00057369...

Then,

3)

4)

I have pages of working on the last two and I'm getting nowhere! Please someone come along and tell me I'm missing something simple! Thankyou!
2. Well that was fun.....sort of.

B1=1507/283920 C1=507/883750

Same values as I had hours ago....checked them and thought I was wrong. I'm too tired for this sort of thing. I keep making stupid mistakes.

If it's any help, what I did was replace all the numbers with extra letters to simplify the algebra.

With
a=-1/10
d=1/1400000
e=-1400
f=101/80
g=-1/100000-1/1400

and

If you're missing something simple then so am I.

I might try the other equations tomorrow.
3. Same approach for the second pair of equations led to a quadratic for B2.

Not surprisingly I couldn't get exact values this time.

I've got answers and they seem to check out ok.

Spoiler:
Show

B2 = -0.0096363.......,C2 = 0.0017627.......

and

B2= 0.00781407....., C2 = 0.000370844......

Let me know if you want any help.

Chances are you just needed to do it with a fresh head like me.

It was far easier after some sleep.

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Updated: November 9, 2008
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