SOLUTION: find the domain of the indicated combined funtion: find the domain of (f+g)(x) when f(x)=8-7x and g(x)=-5x+5. so far i got: f(x)+g(x) (8-7x)+(-5x+5) 13+ -12x

Algebra ->  Rational-functions -> SOLUTION: find the domain of the indicated combined funtion: find the domain of (f+g)(x) when f(x)=8-7x and g(x)=-5x+5. so far i got: f(x)+g(x) (8-7x)+(-5x+5) 13+ -12x      Log On


   

Question 103917: find the domain of the indicated combined funtion:
find the domain of (f+g)(x) when f(x)=8-7x and g(x)=-5x+5.
so far i got:
f(x)+g(x)
(8-7x)+(-5x+5)
13+ -12x
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
%28f%2Bg%29%28x%29 Start with the given combination


f%28x%29%2Bg%28x%29 Break up the combination


%288-7x%29%2B%28-5x%2B5%29 Plug in f%28x%29=8-7x and +g%28x%29=-5x%2B5


%28-7x-5x%29%2B%285%2B8%29 Group like terms


-12x%2B13 Combine like terms


So %28f%2Bg%29%28x%29=-12x%2B13

Notice the domain of both f(x) and g(x) is: x is the element of all real numbers (ie x can be any number for both of them). So the domain for %28f%2Bg%29%28x%29 is the same as the two functions f and g