Hi Bunuel,
I took the LCM of b=1+1/4a
Then b became
5/4aI got the answer as -85/256
Why can't we take the LCM and do it this way?
And if we can then either way, we must get the same answer..
Please help...thanks[/quote]
Hi
zanaik89,
Refer the highlighted portion, It should be :
\(b=1+\frac{1}{4}a\)-------------(2)
=\(\frac{4+a}{4}\) (Though we don't require this step)
a=1+\(\frac{1}{4} + \frac{1}{16} + \frac{1}{64}\)=\(\frac{64+16+4+1}{64}\)=\(\frac{85}{64}\)------------(1)
Hence \(a-b=\frac{85}{64}-(1+\frac{1}{4}*\frac{85}{64})=\frac{85}{64}-1-\frac{85}{4*64}=\frac{(4*85)-(4*64)-85}{4*64}\)=-\(\frac{1}{256}\)
Another Method:-\(a=1+\frac{1}{4}+\frac{1}{16}+\frac{1}{64}\)
So, \(\frac{1}{4}a=\frac{1}{4}+\frac{1}{16}+\frac{1}{64}+\frac{1}{256}\) (Dividing both sides by 4)
So, \(b=1+\frac{1}{4}a=1+\frac{1}{4}+\frac{1}{16}+\frac{1}{64}+\frac{1}{256}\)
Hence, \(a-b=(1+\frac{1}{4}+\frac{1}{16}+\frac{1}{64})-(1+\frac{1}{4}+\frac{1}{16}+\frac{1}{64}+\frac{1}{256})\)
Or, \(a−b=−\frac{1}{256}\)
_________________
Regards,
PKN
Rise above the storm, you will find the sunshine