Question 109844
Let f(x)=4-x^.....do you have here {{{x^2}}} or {{{x}}}?

if you have {{{x^2}}}, then we have:

{{{f(x)=4-x^2}}}
 and {{{g(x)=2-x}}}

 to find {{{f(x)-g(x)}}}.....substitute values for {{{f(x)}}} and {{{g(x)}}}

{{{f(x)-g(x) = (4-x^2) - (2-x)}}}.....

{{{f(x)-g(x) = 4 - x^2 - 2 + x}}}

{{{f(x)-g(x) = - x^2 + x + 2}}}

if you have {{{x}}}, then we will have:

{{{f(x)-g(x) = (4-x) - (2-x)}}}.....

{{{f(x)-g(x) = 4-x - 2 + x}}}.....cancel {{{-x}}} and {{{x}}} 

{{{f(x)-g(x) = 4 - 2 }}}.....

{{{f(x)-g(x) =  2 }}}.....