SOLUTION: the denominator of a fraction is 4 more than the numerator. if 4 is added to the numerator and 7 is added to the denominator, the value of a fraction is 1/2. find the original frac

Algebra ->  Rational-functions -> SOLUTION: the denominator of a fraction is 4 more than the numerator. if 4 is added to the numerator and 7 is added to the denominator, the value of a fraction is 1/2. find the original frac      Log On


   

Question 1048798: the denominator of a fraction is 4 more than the numerator. if 4 is added to the numerator and 7 is added to the denominator, the value of a fraction is 1/2. find the original fraction
Found 2 solutions by ptaylor, chen.aavaz:
Answer by ptaylor(2198) About Me  (Show Source):
You can put this solution on YOUR website!
Let x=numerator
Then x+4=denominator
Soooo
add 4 to numerator=x+4
add 7 to denominator=x+11
Our equation to solve then is:
(x+4)/(x+11)=1/2 multiply both sides by 2(x+11)
2(x+4)=x+11
2x+8=x+11
2x-x=11-8
x=3-----numerator
3+4=7-----denominator
CK
(3+4)/(7+7)=7/14=1/2
Hope this helps----ptaylor

Answer by chen.aavaz(62) About Me  (Show Source):
You can put this solution on YOUR website!
Let the original fraction be
A+=+x%2Fy
Then y+=+x%2B4 so A+=+x%2F%28x%2B4%29
Also:
%28x%2B4%29%2F%28x%2B4%2B7%29+=+1%2F2
%28x%2B4%29%2F%28x%2B11%29+=+1%2F2
2%2A%28x%2B4%29+=+x%2B11
2%2Ax%2B8+=+x%2B11
x+=+3
So the original fraction is 3/7 and the second is 7/14.