Question

Suppose f and g are continuous functions such that

g(9) = 3
and
lim
x → 9
[3f(x) + f(x)g(x)] = 12.
Find
f(9).

Answer 1

[3f(x) + f(x)g(x)] = 12

When x = 9,
[3f(9) + f(9)g(9)] = 12
[3f(9) + 3f(9)] = 12
6f(9) = 12
f(9) = 12/6 = 2
f(9) = 2