1.Consider the sequence
6,13,21,30,a,b,c
Find the value of a,b,c.
2.There are x male rabbits and x female rabbits in a farm.Each female rabbit forms a family with one and only one male rabbit.Each family gives birth to a rabbit in a year.If there are 84 rabbits in farm the nest year,what is the value of
x?
3.Simplify the following expressions.
(a) 6-5×a-3a
(b) -8+4a ÷2a-3a
(c) (4a-7b-6)-(5a-4b+9)
數學知識交流(4)
2011-11-24 3:33 am
回答 (2)
2011-11-24 5:06 am
✔ 最佳答案
1) T(n) = 1/2(n^2+11n)a = T(5) = 1/2(5^2+11(5)) = 40
b = T(6) = 1/2(6^2+11(6)) = 51
c = T(7) = 1/2(7^2+11(7)) = 63
2) x+x+x = 84
x=26
3)
(a) 6-8a
(b) -8+2-3a = -3a-6
(c) 4a-7b-6-5a+4b-9 = -a-3b-15
2011-11-23 21:07:12 補充：
sor
it should be x=28
參考: own knowledge
2011-11-24 5:05 am
1.
6 + 7 = 13
13 +8 = 21
21 + 9 = 30
30 + 10 = a = 40
40 + 11 = b = 51
51 + 12 = c = 63 2.
1 male + 1 female + 1 new rabbit = 3
x male + x female + x new rabbit = 3x = 84
x = 283.
(a) 6-5xa-3a = 6 -8a = 2(3 -4a)
(b) -8+4a ÷2a-3a = -8+ 2 -3a = - 6 -3a = -3(2+a)
(c) (4a-7b-6)-(5a-4b+9) = 4a-7b-6-5a+4b-9 = -a -3b -15
6 + 7 = 13
13 +8 = 21
21 + 9 = 30
30 + 10 = a = 40
40 + 11 = b = 51
51 + 12 = c = 63 2.
1 male + 1 female + 1 new rabbit = 3
x male + x female + x new rabbit = 3x = 84
x = 283.
(a) 6-5xa-3a = 6 -8a = 2(3 -4a)
(b) -8+4a ÷2a-3a = -8+ 2 -3a = - 6 -3a = -3(2+a)
(c) (4a-7b-6)-(5a-4b+9) = 4a-7b-6-5a+4b-9 = -a -3b -15
參考: By me
收錄日期: 2021-04-11 18:50:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20111123000051KK00794