作业帮（1）分解因式：x^2-2x-1 8a^3-b^3 （2）在实数范围内因式分解：x^2-5x+3
来源：学生作业帮 编辑：作业帮 分类：数学作业 时间：2024/05/11 04:21:17
（1）分解因式：x^2-2x-1 8a^3-b^3 （2）在实数范围内因式分解：x^2-5x+3
3x^2+4xy-y^2 (x^2-2x)^2-7(x^2-2x）+12
3x^2+4xy-y^2 (x^2-2x)^2-7(x^2-2x）+12
（1）分解因式：x^2-2x-1
=x²-2x+1-2
=(x-1)²-2
=(x-1+√2)(x-1-√2)
8a^3-b^3
=(2a-b)(4a²+2ab+b²)
（2）在实数范围内因式分
x^2-5x+3
=x²-5x+25/4-13/4
=(x-5/2)²-13/4;
=(x-5/2+√13/2)(x-5/2-√13/2)
3x^2+4xy-y^2
=3x²+4xy+4/3y²-y²/3
=(√3x+2/√3y)²-y²/3
=(√3x+2y/√3+y/√3)(√3x+2y/√3-y/√3)
=3(x+y)(x+y/3)
(x^2-2x)^2-7(x^2-2x）+12 我要详细解答!
=(x²-2x-3)(x²-2x-4)
=(x-3)(x+1)[(x-1)²-5]
=(x-3)(x+1)(x-1+√5)(x-1-√5)
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=x²-2x+1-2
=(x-1)²-2
=(x-1+√2)(x-1-√2)
8a^3-b^3
=(2a-b)(4a²+2ab+b²)
（2）在实数范围内因式分
x^2-5x+3
=x²-5x+25/4-13/4
=(x-5/2)²-13/4;
=(x-5/2+√13/2)(x-5/2-√13/2)
3x^2+4xy-y^2
=3x²+4xy+4/3y²-y²/3
=(√3x+2/√3y)²-y²/3
=(√3x+2y/√3+y/√3)(√3x+2y/√3-y/√3)
=3(x+y)(x+y/3)
(x^2-2x)^2-7(x^2-2x）+12 我要详细解答!
=(x²-2x-3)(x²-2x-4)
=(x-3)(x+1)[(x-1)²-5]
=(x-3)(x+1)(x-1+√5)(x-1-√5)
很高兴为您解答,skyhunter002为您答疑解惑
如果本题有什么不明白可以追问,