Question

Let f(x)=49 -x^2, g(x)=7-x. Find (f-g)(x)

Answer 1

F(x) = -x² + 49
g(x) = -x + 7

(f - g)(x) = (-x² + 49) - (-x + 7)
(f - g)(x) = (-x² + 49) + (x - 7)
(f - g)(x) = -x² + x + 49 - 7
(f - g)(x) = -x² + x + 42

Answer 2

We are given with two functions: (x)=49 -x^2 and g(x)=7-x. To evaluate the value of (f-g)(x), we substitute g(x) to the function f(x). We substitute x by 7-x. Hence the answer is equal to  (f-g)(x) = 49 - (7-x)^2 = 49 - (49 - 14x + x^2) = 14x -x^2