Answer:
P43=4!(4–3)!=241=24
Step-by-step explanation:
There are four choices you can make for the lead reindeer. For each possible choice, there are then three remaining you can choose to fly second, making 4×3=12 choices for the lead pair. For each possible choice there are two remaining reindeer to take up the back position, making 12×2=24 choices for the team of three.
This type of problem is called a permutation problem, and we write Pnr for the number of ways of choosing r items from n possibilities when the order of the items matters. In this case we are choosing 3 reindeer from 4 possibilities, and the order they appear in the flying line does matter, so the answer we want is P43. The general formula is Pnr=n!(n−r)!. For the answer we are looking for we therefore have:
P43=4!(4–3)!=241=24
To organize the expressions according to the number of terms, you should understand what a term is. A term is either a single number or variable, or numbers and variables multiplied together. Terms are separated by + or − signs. It is organized as follows:
2x2y + x2 - 3x + 4
3x + y + z
x + 2xyz
9x2yz
So you can use substitution...which is where you have Y all alone on one side of your equation and then plug it in to the other equation...2x-5=-3x+10 and you.solve for X. So x= 3. Then plug 3 into one of the original equations... Y=2(3)+5. So Y= 11.
Answer:
950
Step-by-step explanation:
The common difference is 4, so the general term can be written:
... an = 14 + 4(n -1)
The value of n for the last term is ...
... 86 = 14 + 4(n -1) . . . . . the computation for the last term, 86
... 72 = 4(n -1) . . . . . . . . . subtract 14
... 18 = n -1 . . . . . . . . . . . divide by 4
... 19 = n . . . . . . . . . . . . . add 1
Your series has 19 terms. The first term is 14 and the last is 86, so the average term is (14+86)/2 = 50. Since there are 19 terms, the sum of them is ...
... 19×50 = 950
