Fraction Manipulation and Substitution problem

[EJnr]

My apologies for submitting this question in the unconventional format of a photo of the written problem but I do not have the software to type this up online.

It is a relatively straight-forward question but I just cannot see at all how they reach the final answer at the bottom by substituting equation 2. in to equation 1.

I believe my use of the rules of combining fractions is what is causing me not to see the solution in this problem and would really appreciate anyones thoughts and solution on this problem.

Thanks so much for your time in advance,

EJnr

 

[EJnr]

Thanks so much for your prompt response JeffM.

Yes you have got it spot on. It is when reaching the final stage:

"(P₁ * P₂² * M) / [P₁² * P₂ * (P₁ + P₂)] =
(P₂ * M) / [P₁ * (P₁ + P₂)], which is equation 3."

This final elimination is not completely intuitive to me. Is it simply that all P1 and P2 multiples on the numerator and denominator cancel one another out whereas those in brackets are treated as separate terms and thereby you reach the answer?

As you can see not being clear on this point means that it appears incredibly messy when trying to simplify the numerator and denominator to reach the final answer.

If you have any sources for practicing or revising this kind of manipulation I would love to hear about them also.

Best Regards and my apologies if I do not reply to any further posts until tomorrow morning (Im based in London right now where it is 00:30 so will be picking up again tomorrow morning ),

EJnr

 

[galactus]

but I do not have the software to type this up online.

You do not need special software. Just type the code in \(\displaystyle tags.

i.e. \(\displaystyle \frac{P_{1}P_{2}^{2}M}{P_{1}+P_{2}}\) is gotten by typing \(\displaystyle \frac{P_{1}P_{2}^{2}M}{P_{1}+P_{2}}\(\displaystyle

Except, the end tag has a / slash.\)\)\)

 

[EJnr]

Thanks so much JeffM that is absolutely clear to me now following the discussion on this thread. As always it is very simple but when I had the first shot at it it seemed very complicated; like I say a typical example. And sorry to hear that you may be losing interest in answering questions on these boards but for what it is worth that was a real assistance to me so your efforts where much appreciated in this instance. Thanks also to galactus for your post, I will bear these points in mind on any future posts.

Enjoy your work all and thanks so much again for your assistance,

EJnr