中二數學(~急~)

2007-09-26 5:00 am

恆等式
求A和B的值
3(2x+A)≡2(Bx-9)

回答 (5)

2007-09-26 5:12 am

✔ 最佳答案

3(2x+A)≡2(Bx-9)

6x + 3A≡2Bx - 18

6x = 2Bx
6=2B
B=3

3A=-18
A=-6

做法通常乘開曬d野....然之後抽公因數(eg. 2x + 3x ≡ bx, 變做 (2 + 3)x ≡ bx ,咁就好易計到邊一個係等於邊一個...

參考: 自己....

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2007-09-26 5:37 am

3(2x+A)≡2(Bx-9)
左方=6x+3A
右方=2Bx-18
因此,
2xB=6x
B=6x/2x
=3
3A=-18
A=-18/3
=-6

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2007-09-26 5:29 am

3(2x+A)≡2(Bx-9)
LHS:3(2x+A)
=6x+3A

RHS:2(Bx-9)
=2Bx-18

THEREFORE;
3A=-18
A =18/3
A =6

6x=2Bx
6 =2B
B =6/2
B = 3

A=6
B=3`

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2007-09-26 5:28 am

3(2x+A)≡2(Bx-9)
LHS=3(2x+A)
=6x+3A
RHS=2(Bx-9)
=2Bx-18
∵6x+3A=2Bx-18
∴6=2B，B=3
3A= -18，A= -6

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2007-09-26 5:07 am

LHS
=3(2x+A)
=6x+3A

RHS
=2(Bx-9)
=2Bx-18

∴6x=2Bx
B=3

3A=-18
A=-6

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