Question

初二因式分解体

Answer 1

1. 2x^2+4xy+2y^2-8z^2

2. ab(c^2-d^2)+cd(a^2-b^2)

3. x^2-4mx+8mn-4n^2

4. x^4+64

5. x^3-11x^2+31x-21

6. x^3-4xy^2-2x^2y+8y^3

7. a+b=2/3,ab=2 求 a^2b+2a^2b^2+ab^2

8. (1/2x2+x-1)+(1/2x^2+3x+1)

9. a+b+c=0 求 a^3+a^2c+b^2c-abc+b63
1. 2x^2+4xy+2y^2-8z^2

=2[(x^2+2xy+y^2) - 4z^2]

=2[(x+y)^2 - (2z)^2]

=2(x+y - 2z)(x+y + 2z)

2. ab(c^2-d^2)+cd(a^2-b^2)

= ab*c^2 - ab*d^2+cd*a^2 - cd*b^2

=ab*c^2+cd*a^2 - (ab*d^2+cd*b^2)

=ac*bc+ac*ad - (bd*ad+bd*bc)

=ac*(bc+ad) - bd*(ad+bc)

=(ad+bc)(ac-bd)

3. x^2-4mx+8mn-4n^2

=x^2-4mx+4m^2-4m^2+8mn-4n^2

= (x-2m)^2-[(2m)^2-8mn+(2n)^2]

= (x-2m)^2-(2m-2n)^2

=(x-2m+2m-2n)[x-2m-(2m-2n)]

=(x-2n)(x-4m+2n)

4. x^4+64

5. x^3-11x^2+31x-21

6. x^3-4xy^2-2x^2y+8y^3

=(x^3-2x^2y) - (4xy^2-8y^3)

=(x^2)*(x-2y) - (4*y^2)*(x-2y)

=(x-2y)[x^2-(2y)^2]

=(x-2y)(x+2y)(x-2y)

=(x+2y)(x-2y)^2

7. a+b=2/3,ab=2 求 a^2b+2a^2b^2+ab^2

8. (1/2x2+x-1)+(1/2x^2+3x+1)

9. a+b+c=0 求 a^3+a^2c+b^2c-abc+b63

Answer 2

哪道题啊

Answer 3

什么题目啊？