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请你说明(4x³+8x²-6x-1)+(1.5x³-4.2x²+3.7x-6)-

来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/21 19:51:39
请你说明(4x³+8x²-6x-1)+(1.5x³-4.2x²+3.7x-6)-(3.8x²-2.3x+5.5x³+15
)的值与x无关
(4x^3+8x^2-6x-1)+(1.5x^3-4.2x^2+3.7x-6)-(3.8x^2-2.3x+5.5x^3+15)
=4x^3+8x^2-6x-1+1.5x^3-4.2x^2+3.7x-6-3.8x^2+2.3x-5.5x^3-15
=(4x^3+1.5x^3-5.5x^3)+(8x^2-4.2x^2-3.8x^2)+(3.7x-6x+2.3x)-1-6-15
=0+0+0-22
=-22
再问: 可不可以简单些
再答: (4x³+8x²-6x-1)+(1.5x³-4.2x²+3.7x-6)-(3.8x²-2.3x+5.5x³+15) =4x^3+8x²-6x-1+1.5x³-4.2x²+3.7x-6-3.8x²+2.3x-5.5x³-15 =(4+1.5-5.5)x³ +(8-4.2-3.8)x² +(3.7-6+2.3)x-1-6-15 =0+0+0-22 =-22