SOLUTION: F is given. Find all values of a for which f(a) is the indicated value. f(x)=x-5/x+1;f(a)=3/5

Algebra ->  Rational-functions -> SOLUTION: F is given. Find all values of a for which f(a) is the indicated value. f(x)=x-5/x+1;f(a)=3/5      Log On


   

Question 1025228: F is given. Find all values of a for which f(a) is the indicated value.
f(x)=x-5/x+1;f(a)=3/5
Found 2 solutions by MathLover1, Edwin McCravy:
Answer by MathLover1(20850) About Me  (Show Source):
Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=%28x-5%29%2F%28x%2B1%29; f%28a%29=3%2F5

Substitute a for x throughout

f%28a%29=%28a-5%29%2F%28a%2B1%29; f%28a%29=3%2F5

Now substitute 3%2F5 for f%28a%29

3%2F5=%28a-5%29%2F%28a%2B1%29

Cross-multiply:

3%28a%2B1%29=5%28a-5%29

3a%2B3=5a-25

-2a=-28

a=14

Edwin