數學功課,plz

1.(x+4)(x+3)
=x^2+3x+4x+12
=x^2+7x+12

2.(a+3)(a+3)
=a^2+3a+3a+9
=a^2+6a+9

3.(b+5)(b+3)
=b^2+3b+5b+15
=b^2+8b+15

4.(x+3)(6x+9)
=6x^2+9x+18x+27
=6x^2+27x+27

5.(2x+4)(x-3)
=2x^2+6x+4x-12
=2x^2+10x-12

6(5a+3)(a-3)
=5a^2-15a+3a-9
=5a^2-12a-9

2012-10-09 21:23:32 補充：
7.(7b+5)(b-3)
=7b^2-21b+5b-15
=7b^2-16b-15

8.(3x+3)(6x-9)
=18x^2-27x+18x-27
=18x^2+9x-27

1.x2次+3X+4X+12=x2次+7x+12
2.a2次+3a+3a+9=a2次+6a+9
3.b2次+3b+5b+15=b2次+8b+15
4.6x2次+9x+18x+27=6x2次+27x+27
5.2x2次-6x+4x-12=2x2次-2x-12
6.5a2次-15a+3a-9=5a2次-12a-9
7.7b2次-21b+5b-15=7b2次-16b-15
8.18x2次-27x+18x-27=18x2次-9x-27
(2次=未知數的右上角寫上細的2)

2012-10-09 21:33:09 補充：
咩野.