can someone solve these equations and tell me how you did it step by step?

2009-12-24 3:27 pm
4x + 8 = 2x + 10 and 3(x - 4) + 5 = 5

回答 (6)

2009-12-24 4:03 pm
✔ 最佳答案
1)
4x + 8 = 2x + 10
4x - 2x = -8 + 10
2x = 2
x = 2/2
x = 1

2)
3(x - 4) + 5 = 5
3(x - 4) = 5 - 5
x - 4 = 0/3
x = 4
2009-12-24 3:59 pm
( i ) 4x + 8 = 2x + 10
( ans ) 4x - 2x = 10 -8
2x = 2
x = 2/2 = 1
therefore x = 1

( ii ) 3( x - 4 ) + 5 = 5
( ans ) 3x - 12 + 5 = 5
3x = 5 - 5 + 12
3x = 0 + 12 = 12
3x = 12
x = 12/3 = 4
therefore x = 4
參考: my brain. only my brain.
2009-12-24 3:35 pm
4x + 8 = 2x + 10
combine like terms and then simplify to solve.
You must always balance the equation.
4x - 2x + 8 = 2x - 2x +10
2x + 8 = 10
Whatever is added or subtracted to one side must be done to the other.
2x + 8 - 8 = 10 -8
2x = 2
divide by 2
x = 1
Plug in original equation to check.
4(1) +8 = 2(1) +10
4+8 = 2 + 10
10 = 10
2009-12-24 3:33 pm
1) 4x - 2x = 10 - 8
2x = 2 therefore x = 1

2) 3x - 12 + 5 = 5
3x = 5 - 5 + 12
3x = 12 therefore x = 4
2009-12-24 3:33 pm
4x + 8 = 2x + 10
-2x -2x
2x + 8 = 10
- 8 = -8
2x = 2
x = 1

3(x-4) + 5 = 5
3x - 12 + 5 = 5
3x - 7 = 5
+7 +7
3x = 12
x = 4
2009-12-24 3:31 pm
2x = 2
x = 1

3x - 12 = 0
x = 4


收錄日期: 2021-05-01 12:55:20
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20091224072743AArWCxa

檢視 Wayback Machine 備份