Solve using substitution. x = –2 5x + 3y = 14
1 answer:
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Answer:
B.
Step-by-step explanation:
Total number of students surveyed = 420
Of which only prefer rap.
So, the number of people who like rap is the product of the fraction of people who prefer rap and the total number of students.
The number of students that prefer rap is 105
So the equation is .
Answer:
Step-by-step explanation:
This is a Combination (as in permutation vs combination) question the symbol (n r) refers to "n choose r". This is sometimes written as nCr
i.e the question is asking you to find how many combinations each will yield when you chose r items from n item without repetition and order does not matter.
I will only do the first question for you and you can just follow the same steps to solve the rest of the questions.
Recall that
Consider question a) we are given (5 1) or ₅C₁
we can see that n = 5 and r = 1
If we substitute this into the formula:
₅C₁ = (5!) / [ (1!)(5- 1)!]
= (5!) / [ (5- 1)!]
= (5!) / (4!)
= (5·4·3·2·1) / (4·3·2·1)
= 5
hence ₅C₁ = 5