A farmer in Gervais is raising zebras and elephant. Last week, she bought 15 bags of feed. Zebra feed costs $35 a bag and elepha
1 answer:
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Answer:
⇒ [Factorized form]
Step-by-step explanation:
Given expression:
We need to make the subject.
In order to do that we need to solve the expression for in terms of
and
We have,
Subtracting both sides by
Taking square root both sides in order to remove square of
The difference of squares can be factorized and written as:
[difference of squares
]
Answer:
35,829,630 melodies
Step-by-step explanation:
There are 12 half-steps in an octave and therefore arrangements of 7 notes if there were no stipulations.
Using complimentary counting, subtract the inadmissible arrangements from to get the number of admissible arrangements.
can be any note, giving us 12 options. Whatever note we choose,
must match it, yielding
. For the remaining two white key notes,
and
, we have 11 options for each (they can be anything but the note we chose for the black keys).
There are three possible arrangements of white key groups and black key groups that are inadmissible:
White key notes can be different, so a distinct arrangement of them will be considered a distinct melody. With 11 notes to choose from per white key, the number of ways to inadmissibly arrange the white keys is .
Therefore, the number of admissible arrangements is: