Question 35754: (x+4)/10=6/(x-3)
Answer by kev82(151)   (Show Source):
You can put this solution on YOUR website! Hi,
We want to find x. At the moment x is in the numerator of one fraction, and the denominator of another. There are a few ways to solve this, but the simplest is to get rid of fractions all together, by multiplying the whole equation by ) . This gives us
(x+4)=60)
Think about what we've just done if  , Does it matter?
We're now left with this equation, which is your bog standard quadratic. This one can be factorised quite easily. (I miss the days when every quadratic I had to solve was factorisable!)
Multiplying out and tidying up gives
Now, there isn't any coeficient in front of the x, and the constant term is negative, so we're looking at something like:
(x-?_2)=0)
Where the question marks multiply to 72, and have a difference of 1. 8, and 9 look like good candidates. So that gives
(x-8)=0)
So from this we can read off that either  or 
Pluging both of these into the original equation shows they both work, so there's your answers.
Hope that helps,
Kev
|
|
|
