-x,2x^2,-3x^,4x^4,-5x^5……-19x^19,20x^20
1x+2x+3x+4x+5x+6x+7x…+99x=100
x+2/x+1-x+3/x+2-x+4/x+3+x+5/x+4
x^5+x^4 = (x^3-x)(x^2+x+1)+x^2+x
找规律:-x,2x^2,-3x^2,4x^2,…,-19x^19,20x^20…
|X-1|+|X-2|+|X-3|+|X-4|+|X-5|+|X-6|+|X-7|+|X-8|+|X-9|+|X-10|
x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少?
若x+x^2+x^3+x^4=0.求x^5+x^6+…+x^2004的值
2x+3x+4x+5x+x+6x+7x=100
通分x+4/x*x+4x与x-5/x(x-5)-2(x-5)
x+2x-3x-4x+5x+6x-7x.-196x+197x+198x-199x-200x 等于多少
X^4-X^3-5X^2-6X-4
(x-4)(2x-5)-(3x-2)(x+6)