分解因式:(x²+3x+2)(4x²+8x+3)-90

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分解因式:(x²+3x+2)(4x²+8x+3)-90分解因式:(x²+3x+2)(4x²+8x+3)-90分解因式:(x²+3x+2)(4x

分解因式:(x²+3x+2)(4x²+8x+3)-90
分解因式:(x²+3x+2)(4x²+8x+3)-90

分解因式:(x²+3x+2)(4x²+8x+3)-90
﹙x²+3x+2)(4x²+8x+3)-90
原式=﹙x+2﹚﹙x+1﹚﹙2x+1﹚﹙2x+3﹚-90
=﹙x+2﹚﹙2x+1﹚﹙x+1﹚﹙2x+3﹚-90
=﹙2x²+5x+2﹚﹙2x²+5x+3﹚-90
设2x²+5x+2=t
=t﹙t+1﹚-90
=t²+t-90
=﹙t+10﹚﹙t-9﹚
=﹙2x²+5x+2+10﹚﹙2x²+5x+2-9﹚
=﹙2x²+5x+12﹚﹙2x²+5x-7﹚
=﹙2x²+5x+12﹚﹙2x+7﹚﹙2x-1﹚

(x+1)(x+2)(2x+3)(2x+1)-90

(x^2+3x+2)(4x^2+8x+3)-90
=(x+2)(x+1)(2x+1)(2x+3)-90
=(x+2)(2x+1)(x+1)(2x+3)-90
=(2x^2+5x+2)(2x^2+5x+3)-90
=(2x^2+5x)^2+5(2x^2+5x)+6-90
=(2x^2+5x)^2+5(2x^2+5x)-84
=(2x^2+5...

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(x^2+3x+2)(4x^2+8x+3)-90
=(x+2)(x+1)(2x+1)(2x+3)-90
=(x+2)(2x+1)(x+1)(2x+3)-90
=(2x^2+5x+2)(2x^2+5x+3)-90
=(2x^2+5x)^2+5(2x^2+5x)+6-90
=(2x^2+5x)^2+5(2x^2+5x)-84
=(2x^2+5x-7)(2x^2+5x+12)
=(2x+7)(x-1)(2x^2+5x+12)

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