630-x+2/5x=4x等于?

630-x+2/5x=4x等于? x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? (x-1)(x-2)(x-3)(x-4)=(x+5)(x+6)(x+7)求X等于几? 4x-3(x-5)=2x+(x-1) x等于多少 x+2x-3x-4x+5x+6x-7x.-196x+197x+198x-199x-200x 等于多少 2x(5x+3)=3x(5x+3x)中x等于多少 已知函数f(x)={根号x(x大于等于0),-x^2-4x (x 5/2x-x等于15/4 3x+5x=?x等于 x+(x-4)为什么等于2x 2x+1/x-4=2x+1/x-5 方程 等于多少 f(x-1)=x^2+4x-5,则f(x+1)等于