4x+2.5x*(x十0.85)=13.5 方程的解

x的平方十x(x十4)=30, 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 4x+2.5x*(x十0.85)=13.5 方程的解 已知f（x）=2X十|,X≥O;X^2十4,x x十2.5x=0.7 5x十4x=36 4(X十3)=6x 4(x十5)+x=80 2(x-7)=x十4 4X十3(X十1)=31 x^2十2x十1=4 X十3X十4=24怎么解? x十24十x=34 X十1十4/5X=1十7/8(X-1)十(X一1)怎么算 2x十8十3x十8十4x十8=?请算出这道题目求士寸佰了⑥ X.(X十1)x(X十2)x(x十3) =360 一(x2十3X)十2(4X十x2),其中X=一2 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)=