Y = k/x for some fixed number constant k
7 = k/9
k = 63
so Y = 63/x
14 = 63/x
14 x = 63
x = 63/14 = 9/2
Answer:
a
Step-by-step explanation Option 1:
Plug
4
into
g
(
x
)
:
g
(
x
)
=
−
2
(
4
)
−
6
=
−
8
−
6
=
−
14
Then plug
g
(
x
)
into
f
(
x
)
:
f
(
x
)
=
3
(
−
14
)
−
7
=
−
42
−
7
=
−
49
Option 2:
Plug
g
(
x
)
into
f
(
x
)
:
f
(
x
)
=
3
(
−
2
x
−
6
)
−
7
=
−
6
x
−
18
−
7
=
−
6
x
−
25
Finally plug
4
into our current
f
(
x
)
:
f
(
x
)
=
−
6
(
4
)
−
25
=
−
24
−
25
=
−
49
Answer: 20%
Step-by-step explanation:
To solve this problem you must apply the proccedure shown below:
1. You must apply the following formula (Let's call the percent of increase:):
2. Substitute values and solve:
%
The probability of pressing a white key is 13/22. This solution can be obtained by dividing 52 by 88 which is the total number of keys on the modern piano.