SOLUTION: In a certain fraction, the denominator is 2 less than the numerator. If 1 is added to both the numerator and denominator, the resulting fraction is equal to 9/7. Find the origina

Algebra ->  Test -> SOLUTION: In a certain fraction, the denominator is 2 less than the numerator. If 1 is added to both the numerator and denominator, the resulting fraction is equal to 9/7. Find the origina      Log On


   

Question 923328: In a certain fraction, the denominator is 2 less than the numerator. If 1 is added to both the numerator and denominator, the resulting fraction is equal to
9/7. Find the original fraction.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
In a certain fraction, the denominator is 2 less than the numerator.
d = n-2
If 1 is added to both the numerator and denominator, the resulting fraction is equal to 9/7.
%28%28n%2B1%29%29%2F%28%28d%2B1%29%29 = 9%2F7
Find the original fraction.
Cross multiply
9(d+1) = 7(n+1)
9d + 9 = 7n + 7
9d = 7n + 7 - 9
9d = 7n - 2
replace d with (n-2)
9(n-2) = 7n - 2
9n - 18 = 7n - 2
9n - 7n = -2 + 18
2n = 16
n = 8
then obviously
d = 6
8%2F6 is the original equation
:
you can check this for yourself