An easier way to think of this problem is just keep adding for each additional hour:
0.5 hours --> $2
1.5 hrs --> $3.75
2.5 hrs --> $5.50
3.5 hrs --> $7.25
and since you can only spend $7, the maximum time is 2.5 hours
The answers are
f
o
g
(
x
)
=
−
2
x
+
23
and
g
o
f
(
x
)
=
−
2
x
+
5
Explanation:
f
(
x
)
=
−
2
x
+
11
g
(
x
)
=
x
−
6
f
o
g
(
x
)
=
f
(
g
(
x
)
)
=
f
(
x
−
6
)
=
−
2
(
x
−
6
)
+
11
=
−
2
x
+
12
+
11
=
−
2
x
+
23
g
o
f
(
x
)
=
g
(
f
(
x
)
)
=
g
(
−
2
x
+
11
)
=
−
2
x
+
11
−
6
=
−
2
x
+
5
I think that the equations speak by themselves.
Of course,
f
o
g
(
x
)
≠
g
o
f
(
x
)
A: 95 people dislike both
B: 81
C: 21
