Question

八年级数学分解因式

①-a^+4
②4(3p+5q)-9(2p-q)^2
③2(x+y)^3-8(x+y)
④16x^4-8x^2+1
⑤9-6(a+b)+(a+b)^2
⑥a^3-4a^2b+4ab^2
⑦(a-b)^3-2(b-a)^2+(a-b)
⑧(x+y）^2-4x^2y^2
⑨9（m+n)^2-4(m-n)^2
⑩x^3-4x^2+4x

Answer 1

①-a^+4
=4-a^2
=(a+2)(2-a)

②4(3p+5q)^2-9(2p-q)^2
=[2(3p+5q)+3(2p-q)][2(3p+5q)-3(2p-q)]
=(6p+10q+6p-3q)(6p+10q-6p+3q)
=13q(12p+7q)

③2(x+y)^3-8(x+y)
=2(x+y)[(x+y)^2-4]
=2(x+y)(x+y+2)(x+y-2)

④16x^4-8x^2+1
=(4x^2-1)^2
=(2x+1)^2(2x-1)^2

⑤9-6(a+b)+(a+b)^2
=(3-a-b)^2

⑥a^3-4a^2b+4ab^2
=a(a^2-4ab+4b^2)
=a(a-2b)^2

⑦(a-b)^3-2(b-a)^2+(a-b)
=(a-b)[(a-b)^2-2(a-b)+1]
=(a-b)(a-b-1)^2

⑧(x+y）^2-4x^2y^2
=(x+y+2xy)(x+y-2xy)

⑨9（m+n)^2-4(m-n)^2
=[3(m+n)+2(m-n)][3(m+n)-2(m-n)]
=(3m+3n+2m-2n)(3m+3n-2m+2n)
=(5m+n)(m+5n)

⑩x^3-4x^2+4x
=x(x^2-4x+4)
=x(x-2)^2

Answer 2

①-a^2+4=(2+a)(2-a)
②4(3p+5q)-9(2p-q)^2
③2(x+y)^3-8(x+y)=(
④16x^4-8x^2+1
⑤9-6(a+b)+(a+b)^2
⑥a^3-4a^2b+4ab^2
⑦(a-b)^3-2(b-a)^2+(a-b)
⑧(x+y）^2-4x^2y^2
⑨9（m+n)^2-4(m-n)^2
⑩x^3-4x^2+4x -----题目中错误太多！！！

Answer 3

先给你做其中两道题
2(x+y)^3-8(x+y)=2（x+y)（x+y+2)（x+y-2)
16x^4-8x^2+1=（2x+1）^2（2x-1）^2
第一题好像出错了吧，，其余的题还需要答案吗？？