(x+4)(x-4)-(x-2)(x十8

(x+4)(x-4)-(x-2)(x十8 已知1十x十x^2 十x^3=0,求x十x^2十x^3十x^4+x^5十x^6+x^7十x^8的值 1/(x^2一4x十3)十1/(x^2一8x十15)十1/(x^2-12x十35)十1/(x^2一16x十63)= 2x十8十3x十8十4x十8=?请算出这道题目求士寸佰了⑥ 已知f（x）=2X十|,X≥O;X^2十4,x 因式分解:(x^2十3x一3)(x^2十3x十4)一8 x十4·x+2 2(x-7)=x十4 6x一4≤3 2一X≤X十3 3X一2>X十8 *-----------------------------------------------*| 6 4 X | 8 X X | X X 5 || X X X | X X X | X 7 8 || X X X | X X X | X X X ||---------------+---------------+--------------- || X X X | X X X | 5 1 X || X X X | X 6 X | X X X || 8 X X | 3 5 X | 2 X X || 2(3X十2)二4(X十4) x^2十2x十1=4 X十1十4/5X=1十7/8(X-1)十(X一1)怎么算 8x的平方-【7x-(4x-3)十3】十4x (x十3)(x十4)一x(x+2)一5 x的平方十x(x十4)=30, 4x十2(8一x)=26 1/x^2一6x十8=1/x^2一4x十3x^2一6x十8和x^2一4x十3