Maths

2011-08-13 6:26 pm

Try to do the multiplications of the following algebraic expressions.

1. 2x(3x-4)

2. (9-m)(4m)

Correct the mistakes in the following questions.

1. 2x+3x(2次方)+x-x(2次方)
=3x+x(2次方)
=4X(3次方)

2. 2分之8x+4-(3-2)
=4x+4-3x-2
=x+2

3. 2分之5(a-1)-3分之4(a+1)
=15(a-1)-8(a+1)
=15a-15-8(a+1)
=7a-23

更新1:

For each expression below,each letter repressents a distinct number from 0 to 9.Try to find out the value of each of them. 1. AA X AB -------- ACB 2. AB - BA ---------- BC

回答 (2)

chauncey

2011-08-13 8:54 pm

✔ 最佳答案

1. 2x(3x-4)
6x^2-8x

2. (9-m)(4m)
-4m^2+36m

1. 2x+3x^2+x-x^2
=2x^2+3x

2. (8/2x)+4-(3-2)
=4x+4-1
=4x+3

3. 5/2(a-1)-4/3(a+1)
=2.5(a-1)-1.33(a+1)
=2.5a-2.5-1.33a-1.33
=1.17a-3.83第3條可用分數做
5/2(a-1)-4/3(a+1)
=(5/2a)-5/2(-4/3a)-4/3
=(5/2a-4/3a)-5/2-4/3
=7/6a-23/6

👍 0 👎 0

2011-08-13 6:41 pm

1. 2x(3x-4)
6x^2-8x

2. (9-m)(4m)
-4m^2+36m

1. 2x+3x^2+x-x^2
=2x^2+3x

2. (8/2x)+4-(3-2)
=4x+4-1
=4x+3

3. 5/2(a-1)-4/3(a+1)
=2.5(a-1)-1.33(a+1)
=2.5a-2.5-1.33a-1.33
=1.17a-3.83

2011-08-13 10:45:26 補充：
第3條可用分數做
5/2(a-1)-4/3(a+1)
=(5/2a)-5/2(-4/3a)-4/3
=(5/2a-4/3a)-5/2-4/3
=7/6a-23/6

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