Solve Ratio Question: (3a + 3b)/(a - b) with a/b = 2/5 | Get Homework Help

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To solve the expression (3a + 3b)/(a - b) given the ratio a/b = 2/5, first express 'a' in terms of 'b' as a = (2/5)b. Substituting this into the expression allows for simplification. The discussion also includes a separate problem involving the variables K, l, and m, with hints provided for solving ratios. Participants encourage showing calculations for clarity and understanding. The focus remains on solving ratio-based problems effectively.
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Homework Statement



Calculate: (3 a + 3 b)/(a - b) If a/b = 2/5

No attempts, I don't know how to solve this.

Help?
 
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welcome to pf!

hi blunted! welcome to pf! :smile:
blunted said:
a/b = 2/5

hint: so a = … ? :wink:
 
Oh my god :D

Thanks for the hint and the welcome :)
 
K + l + m = 34.
K/l = 1/4
l/m = 1/3

l = ?

Is it 8 ?
 
Last edited:
maybe it is and maybe it isn't :wink:

show your calculations! :smile:

(same hint as before, btw)
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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