7x+3(13-5x)=-1怎么算

7x-3(2/3x+1/5x)-(x+2/5x)+2x,=5x怎么求出 3x-1+5x=7x+x-3x这个方程怎么解 2(x-1)(x+5)-3(x-2)-4x=2x的平方+7方程题怎么算? 1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550 3(1/3x-1/5x)=x-1-1/3x-1/5x 这道题怎么算? 7x(x-6)+3x=4x(2x+5)怎么解这个方程 (x+3):(x-1)=7:3 这道题怎么算 已知3x*x-x=1,求6x*x*x+7x*x-5x+2000 用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. (2x-1)/(x-1)(x-2)=(x-5)/(x-2)(x-3) x/2x^2-11x-21=(x+7)/x^2-1 y=(x-1)(x-2)(x-3)(x-4)(x-5)(x-6)(x-7)(x-8)(x-9)(x-10)的导数在x=1 已知1+x+x^2+x^3=0,求x+x^2+x^3+x^4+x^5+x^6+x^7+x^8的值