Thread: A is two-third of the sum of B and C. B is three-quarter of the sum of A and C.

A is two-third of the sum of B and C. B is three-quarter of the sum of A and C. Express A as a fraction of B.

Hello dtay

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Originally Posted by dtay

A is two-third of the sum of B and C. B is three-quarter of the sum of A and C. Express A as a fraction of B.

You need to create two equations involving and , and then eliminate to find an equation involving just and .

Here are some clues:

The first statement can be written:

So if we multiply by

(1)

Now write down the second statement in a similar way, and use equation (1) to eliminate .

Then re-arrange so that you have on one side, and on the other. Finally, divide both sides by to find . I get the answer:



Can you fill in the gaps?

Grandad

Thank You very much, Grandad.
I understand it already, and i also have found out another method, using
common ratio.
I'm sorry i wasn't able to thank you earlier.
Thank you very much for helping me!