分解因式(x'2十x一6)(x'2十x一8)一24;(x十1)(x一2)(x一3)(x一6)十20;
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分解因式(x'2十x一6)(x'2十x一8)一24;(x十1)(x一2)(x一3)(x一6)十20;
(x²+x-6)(x²+x-8)-24
=(x²+x-6)[(x²+x-6)-2]-24
=(x²+x-6)²-2(x²+x-6)-24
=[(x²+x-6)-6][(x²+x-6)+4]
=(x²+x-12)(x²+x-2)
=(x-3)(x+4)(x-1)(x+2)
(x+1)(x-2)(x-3)(x-6)+20
=[(x+1)(x-6)][(x-2)(x-3)]+20
=(x²-5x-6)(x²-5x+6)+20
=(x²-5x)²-36+20
=(x²-5x)²-16
=(x²-5x+4)(x²-5x-4)
=(x-1)(x-4)(x²-5x-4) (有理数范围内到此为止)
=(x-1)(x-4)[x-(5+√41)/2][x-(5-√41)/2] (实数范围内)
=(x²+x-6)[(x²+x-6)-2]-24
=(x²+x-6)²-2(x²+x-6)-24
=[(x²+x-6)-6][(x²+x-6)+4]
=(x²+x-12)(x²+x-2)
=(x-3)(x+4)(x-1)(x+2)
(x+1)(x-2)(x-3)(x-6)+20
=[(x+1)(x-6)][(x-2)(x-3)]+20
=(x²-5x-6)(x²-5x+6)+20
=(x²-5x)²-36+20
=(x²-5x)²-16
=(x²-5x+4)(x²-5x-4)
=(x-1)(x-4)(x²-5x-4) (有理数范围内到此为止)
=(x-1)(x-4)[x-(5+√41)/2][x-(5-√41)/2] (实数范围内)
分解因式(x十1)(x十2)(x十3)(x十6)一3x'2;3x(3x一2)一a(a十2)
(X十y)的平方一2X一2y十1分解因式
化简求值:(X一3)(X一2)十(X一1)(X十3)一2(X平方一X十8)(其中X=6).
5(x一2)十8<6(x一l)十7
(X十2)(X一13)一16=(X十3)( )
x*3一3x十2分解因式
(x的次方一X十4)X一(X一1)(x的次方十2)=x十7
(1)(X一3)(X一2)十18=(X十9)(X十1) (2)(3X十4)(3X一4)<9(X一2
(2X一)(X十3)=3X十5
解方程 (1)4X^2一4X十1=8 (2)X^2十X一1=0 (3)X^2十6分之一x一3分之一=0
计算:6x2一(2x一1)(3x一2)十(x十2)(x一2)一x(x十7)这题怎么做?
试说明:代数式(2X十3)(6X十2)一6X(2X十l3)十8(7X十2)的值与X的取值无关.