Simplify the following algebraic expressions.
1. 3x+x-2x
2. 5m-5-2(2m+1)
3. 3r+4s-2r+7s
4. a+2b+3c+4a-6b-2c
5. 2xy+3x-2y+4x-6y+5xy
中一數學題
2007-08-23 6:50 am
回答 (8)
2007-09-02 7:50 am
1. 3x+x-2x
=4x-2x
=2x
2. 5m-5-2(2m+1)
=5m-5-4m-2
=5m-4m-5-2
=m-7
3. 3r+4s-2r+7s
=3r-2r+4s+7s
=r+11s
4. a+2b+3c+4a-6b-2c
=a+4a+2b-6b+3c-2c
=5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy
=2xy+5xy+3x+4x-2y-6y
=7xy+7x-8y
it is very easy
因為我已升Form 3(中三)
this is 代數式加減法和因式分解
=4x-2x
=2x
2. 5m-5-2(2m+1)
=5m-5-4m-2
=5m-4m-5-2
=m-7
3. 3r+4s-2r+7s
=3r-2r+4s+7s
=r+11s
4. a+2b+3c+4a-6b-2c
=a+4a+2b-6b+3c-2c
=5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy
=2xy+5xy+3x+4x-2y-6y
=7xy+7x-8y
it is very easy
因為我已升Form 3(中三)
this is 代數式加減法和因式分解
參考: me 的中一知識
2007-08-23 6:54 pm
1)3x+x-2x
=2x
2)5m-5-2(2m+1)
=5m-5-4m-2
=m-7
3)3r+4s-2r+7s
=r+11s
4)a+2b+3c+4a-6b-2c
=5a-4b+c
5)2xy+3x-2y+4x-6y+5xy
=7xy+7x-8y
=2x
2)5m-5-2(2m+1)
=5m-5-4m-2
=m-7
3)3r+4s-2r+7s
=r+11s
4)a+2b+3c+4a-6b-2c
=5a-4b+c
5)2xy+3x-2y+4x-6y+5xy
=7xy+7x-8y
2007-08-23 5:25 pm
1. 3x + x - 2x
= 2x
2. 5m - 5 - 2 (2m + 1)
= 5m - 5 - 4m - 2
= m - 7
3. 3r + 4s - 2r + 7s
= 11s + r
4. a + 2b + 3c + 4a - 6b - 2c
= 5a - 4b + c
5. 2xy + 3x - 2y + 4x - 6y + 5xy
= 7xy + 7x - 8y
= 2x
2. 5m - 5 - 2 (2m + 1)
= 5m - 5 - 4m - 2
= m - 7
3. 3r + 4s - 2r + 7s
= 11s + r
4. a + 2b + 3c + 4a - 6b - 2c
= 5a - 4b + c
5. 2xy + 3x - 2y + 4x - 6y + 5xy
= 7xy + 7x - 8y
2007-08-23 8:41 am
1. 3x+x-2x
=4x-2x = 2x
2. 5m-5-2(2m+1)
=5m-5-4m-2 = m-7
3. 3r+4s-2r+7s
=r+11s
4. a+2b+3c+4a-6b-2c
= 5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy
=7xy+7x-8y
=4x-2x = 2x
2. 5m-5-2(2m+1)
=5m-5-4m-2 = m-7
3. 3r+4s-2r+7s
=r+11s
4. a+2b+3c+4a-6b-2c
= 5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy
=7xy+7x-8y
參考: me
2007-08-23 7:23 am
1. 3x+x-2x
=4x-2x
=2x
2. 5m-5-2(2m+1)
=5m-5-(2)(2m)-(2)(1)
=5m-5-4m-2
=5m-4m-5-2
=m-7
3. 3r+4s-2r+7s
=3r-2r+4s+7s
=r+11s
4. a+2b+3c+4a-6b-2c
=a+4a+2b-6b+3c-2c
=5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy
=2xy+5xy+3x+4x-2y-6y
=7xy+7x-8y
=4x-2x
=2x
2. 5m-5-2(2m+1)
=5m-5-(2)(2m)-(2)(1)
=5m-5-4m-2
=5m-4m-5-2
=m-7
3. 3r+4s-2r+7s
=3r-2r+4s+7s
=r+11s
4. a+2b+3c+4a-6b-2c
=a+4a+2b-6b+3c-2c
=5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy
=2xy+5xy+3x+4x-2y-6y
=7xy+7x-8y
2007-08-23 7:07 am
1. 3x+x-2x = 4x-2x =2x
2. 5m-5-2(2m+1) = 5m-5-4m-2 = m-7
3. 3r+4s-2r+7s = 3r-2r+4s+7s = r+11s
4. a+2b+3c+4a-6b-2c = a+4a+2b-6b+3c-2c = 5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy = 2xy+5xy+3x+4x-2y-6y = 7xy+7x-8y
2. 5m-5-2(2m+1) = 5m-5-4m-2 = m-7
3. 3r+4s-2r+7s = 3r-2r+4s+7s = r+11s
4. a+2b+3c+4a-6b-2c = a+4a+2b-6b+3c-2c = 5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy = 2xy+5xy+3x+4x-2y-6y = 7xy+7x-8y
參考: 我升中4-v-信我啦=]
2007-08-23 6:59 am
1. 3x+x-2x = 2x
2. 5m-5-2(2m+1) = m-3
3. 3r+4s-2r+7s = r+11s
4. a+2b+3c+4a-6b-2c = 5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy = 7xy+7x-8y
希望冇錯啦....哈哈
2007-08-22 23:00:43 補充：
2. 5m-5-2(2m 1) = m-7一時睇錯 *o*
2. 5m-5-2(2m+1) = m-3
3. 3r+4s-2r+7s = r+11s
4. a+2b+3c+4a-6b-2c = 5a-4b+c
5. 2xy+3x-2y+4x-6y+5xy = 7xy+7x-8y
希望冇錯啦....哈哈
2007-08-22 23:00:43 補充：
2. 5m-5-2(2m 1) = m-7一時睇錯 *o*
參考: 自己
2007-08-23 6:55 am
1. 4x-2x = 2x
2. 5m-5-4m-2 = m-7
3. r+11s
4. 5a-4b+c
5. 7xy+7x-8y
2. 5m-5-4m-2 = m-7
3. r+11s
4. 5a-4b+c
5. 7xy+7x-8y
參考: me
收錄日期: 2021-04-13 15:01:38
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070822000051KK06119