F.1 代數加減4題～10分！！

1.(8a-b+2c)+(-b-3c+6a)-(8c+7a-6a)
=8a-b+2c-b-3c+6a-8c-7a+6a
=7a-2b-9c

2.(2c-x+1)-(6x-7c)+(4-5x)
=2c-x+1-6x+7c+4-5x
=9c-12x+5

4.3x(x-2)+4(3x-5)
.....2
=3x -6x+12x-20
.....2
=3x +6x-20
那些點不關事。（因爲平方寫不出來）
第三題不懂得寫。

1.(8a-b+2c)+(-b-3c+6a)-(8c+7a-6a)
=8a-b+2c+-b-3c+6a-8c-7a+6a
=13a-2b-9c
2.(2c-x+1)-(6x-7c)+(4-5x)
=2c-x+1-6x+7c+4-5x
=9c-12x+12
3.1-(2b-1/2a)+(2a+1/2b-3/2)
=1-2b+1/2a+2a+1/2b-3/2
=-1/2-3/2b+5/2a
4.3x(x-2)+4(3x-5)
=3x-6+12x-20
=15x-26

1.
(8a-b+2c)+(-b-3c+6a)-(8c+7a-6a)
=8a-b+2c-b-3c+6a-8c-7a+6a
=13a-2b-9c

2.
(2c-x+1)-(6x-7c)+(4-5x)
=2c-x+1-6x+7c+4-5x
=9c-11x+5

1.(8a-b+2c)+(-b-3c+6a)-(8c+7a-6a)
=8a-b+2c+-b-3c+6a-8c-7a+6a
=13a-2b-9c

2.(2c-x+1)-(6x-7c)+(4-5x)
=2c-x+1-6x+7c+4-5x
=9c-12x+12

3.1-(2b-1/2a)+(2a+1/2b-3/2)
=1-2b+1/2a+2a+1/2b-3/2
=-1/2-3/2b+5/2a

4.3x(x-2)+4(3x-5)
=3x-6+12x-20
=15x-26

2007-10-22 18:47:01 補充：
第二個做法(唔明你想話3x x (x-2)定3 x (x-2))3x(x-2)+4(3x-5)=3x^2-6x+12x-20=3x^2+6x-20

1.(8a-b+2c)+(-b-3c+6a)-(8c+7a-6a)

=8a-b+2c-b-3c+6a-8c-7a+6a

=13a-2b-9c


2.(2c-x+1)-(6x-7c)+(4-5x)

=2c-x+1-6x+7c+4-5x

=9c-12x+5