7.9-5x=7.8/2

x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 解方程x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6) (x+12)(x-2)+(x+7)(x+8)-(x+5)(x-10),其中x=2 x(x-2)-2x(x+1)-3x(x-5) 其中x=负½ (x-3/x-2)-(x-2/x-1)=(x-5/x4) -(x-4/x-3) x-2x+3x-4x+5x.+99x-100x=25求解 2x+3x+4x+5x+x+6x+7x=100 x(x+1)+(x+2)+(x+3)+(x+4)+(x+5) = 27求x f(x,-x)=x^2+2x,fx(x,-x)=5x+1,则fy(x,-x)= 7.9-5x=7.8/2 x+2/x+1-x+4/x+3=x+6/x+5-x+8/x+7 x=? x^5-2x^3+x=? 写过程x(x-1)+2x(x+1)-3x(2x-5)-x(3x-2)+2x(2-x)=-5x(x-2)-4 12.4x-7.8x=23 5(x-1.9)=10.5 3x-2.6x=0.25乘于2 5x/(x-2)-2=3(x-2)/x 7x^2-5x=2x^2+x (5x-2)*(x+8)=5x*x+98 2x(x-1)-x(2x-5)=15