x四次方-x三次方-5x²-6x-4因式分解还有x三次方+(2a+1)x²+(a²+2a-1)x+a²-1
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![x四次方-x三次方-5x²-6x-4因式分解还有x三次方+(2a+1)x²+(a²+2a-1)x+a²-1](/uploads/image/z/806400-0-0.jpg?t=x%E5%9B%9B%E6%AC%A1%E6%96%B9-x%E4%B8%89%E6%AC%A1%E6%96%B9-5x%26%23178%3B-6x-4%E5%9B%A0%E5%BC%8F%E5%88%86%E8%A7%A3%E8%BF%98%E6%9C%89x%E4%B8%89%E6%AC%A1%E6%96%B9%2B%EF%BC%882a%2B1%EF%BC%89x%26%23178%3B%2B%EF%BC%88a%26%23178%3B%2B2a-1%EF%BC%89x%2Ba%26%23178%3B-1)
x四次方-x三次方-5x²-6x-4因式分解还有x三次方+(2a+1)x²+(a²+2a-1)x+a²-1
x四次方-x三次方-5x²-6x-4因式分解
还有x三次方+(2a+1)x²+(a²+2a-1)x+a²-1
x四次方-x三次方-5x²-6x-4因式分解还有x三次方+(2a+1)x²+(a²+2a-1)x+a²-1
x^4-x^3-5x^2-6x-4
=(x^2+ax+b)(x^2+cx+d)
=x^4+(a+c)x^3+(ac+b+d)x^2+(ad+bc)x+bd
由于x的相同次数的项的系数要相等
所以
a+c=-1,
ac+b+d=-5,
ad+bc=-6,
bd=-4.
解得a=1,b=1,c=-2,d=-4.
则x^4-x^3-5x^2-6x-4=(x^2+x+1)(x^2-2x-4)
第二题
x³+(2a+1)x²+(a²+2a-1)x+(a²-1)
=x³+2ax²+a²x+x²+2ax-x+a²-1
=x(x²+2ax+a²)+(x²+2ax+a²)-x-1
=x(x+a)²+(x+a)...
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第二题
x³+(2a+1)x²+(a²+2a-1)x+(a²-1)
=x³+2ax²+a²x+x²+2ax-x+a²-1
=x(x²+2ax+a²)+(x²+2ax+a²)-x-1
=x(x+a)²+(x+a)²-(x+1)
=(x+a)²(x+1)-(x+1)
=(x+1)[(x+a)²-1]
=(x+1)(x+a+1)(x+a-1)
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