In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data
f(x) = x
g (x) = ?
Step 02:
translated
1 up ===> y + 1
y = x
y + 1 = x
y = x - 1
reflected across the y- axis
(x , y) ===> (- x , y)
y = - x - 1
The answer is:
g(x) = - x - 1