# Thread: Partial fractions in chemical kinetics

1. ## Partial fractions in chemical kinetics

Hello,
I ' m studying chemical kinetics and found one mathematical problem.
Please, can you help me ?
I found in book, that the expression 1/(a-x)2(b-x) is decomposed into partial fractions like:
1/(a-x)2(b-x) = (R1x+R2)/(a-x)2 + R3/(b-x)
Why is wrong next expression? :
1/(a-x)2(b-x) = R1/(a-x) + R2/(a-x)2 + R3/(b-x)

a,b
are
initial concentrations (>0)

For sure, I've attached the handwritten text.

Thank you very much for help

Kevin

2. ## Re: Partial fractions in chemical kinetics

the two are equivalent since

$\displaystyle \frac{R_1x+R_2}{(x-a)^2}=\frac{R_1}{x-a}+\frac{a R_1+R_2}{(x-a)^2}$