I would but my teacher has a ad blocker on and I cant access the attachment :P
Answer:NIce
Step-by-step explanation:
Answer:
31465 ways
Step-by-step explanation:
Given data
Let us apply the combination formula
nCr = n! / r! * (n - r)!
n= 31
r= 4
substitute
= 31!/4!(31-4)!
= 31!/4!(27)!
= 31*30*29*28*27!/ 4!(27)!
= 31*30*29*28/4!
=31*30*29*28/4*3*2*1
=755160/24
=31465 ways
Hence there are 31465 possible ways to rank it
Answer:
11, 14, 17, 20
Step-by-step explanation:
An arithmetic sequence has a common difference d between consecutive terms.
Consider 2, 6, 18, 54
6 - 2 = 4, 18 - 6 = 12, 54 - 18 = 36 ← no common difference, not arithmetic
Consider 3, 6, 12, 24
6 - 3 = 3, 12 - 6 = 6, 24 - 12 = 12 ← no common difference, not arithmetic
Consider 11, 14, 17, 20
14 - 11 = 3, 17 - 14 = 3, 20 - 17 = 3 ← common difference of 3, so arithmetic
Consider 7, 11, 13, 18
11 - 7 = 4, 13 - 11 = 2, 18 - 13 = 5 ← no common difference, not arithmetic
The arithmetic sequence is 11, 14, 17, 20
So use cancelation
multiply first equation by 2
2x+8y=10
times 2
4x+16y=20
now add
4x+16y=20
<u>-4x-9y=-13 +
</u>0x+7y=7
7y=7
divide by 7
y=1
subsittue
2x+8y=10
2x+8(1)=10
2x+8=10
subtract 8 from both sides
2x=2
divide by 2
x=1
x=1
y=1
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