Will mark as brainliest ❤️
Answer:
is just a "place-holder" or "variable.
If
f
x
=
x
+
7
then (using a different variable)
f
(
t
)
=
t
+
5
or
using a constant
f
(
x
)
=
5
+
7
Since
5
+
7
=
12
for the given example
f
(
5
)
=
12