x/45-x/50=4

x/45-x/50=4 50x(x-1)+60x(x-4)=5100 六题解方程：x+75%x=140 x-40%x=96 x-76%x=36 4x+50%x=90 60%x-30=120 x+50%x=45 (4/x-5)+(x-3)/(12-x)=(x-45)/(x^2-17x+60) x+ x+(x*50%)=1.5X? X-X/12-X/7-X/8-X/4-X/20-X/5-30-120-300=50解方程 一个“整式的乘法”的问题请先阅读下列解题过程,再仿做下面的问题.已知X*X + X - 1=0,求X*X*X + 2*X*X + 3的值.解X*X*X + 2X*X +3=X*X*X +X*X -X +X*X +X +3=X{X*X +X -1} +X*X +X -1 +4=0+0+4=4+ x + X*X + X*X*X=0.+ X*X + X*X*X 45x+10 =50X（x-1） =(x^2-5x)^2+10(x^2-5x)+24 =x^4-10x^3+25x^2+10x^2-50x+24 这是怎么转化的(X-1)(X-2)(X-3)(X-4) =(X-1)(X-4) (X-2)(X-3)=（x^2-5x+4)(x^2-5x+6)=(x^2-5x)^2+10(x^2-5x)+24=x^4-10x^3+25x^2+10x^2-50x+24=x^4-10x^3+35x^2-50x+24 =（x^2-5x+4)(x^2-5x+6) =(x^2-5x)^2+10(x^2-5x)+24 是怎么转化的(X-1)(X-2)(X-3)(X-4) =(X-1)(X-4) (X-2)(X-3)=（x^2-5x+4)(x^2-5x+6)=(x^2-5x)^2+10(x^2-5x)+24=x^4-10x^3+25x^2+10x^2-50x+24=x^4-10x^3+35x^2-50x+24不好意思我弄错了，是=（x^2-5 45X=（4-X）*30 X=1.6 (1+2x)(1+4x)=45,求x x/50-4=x/60+2 x=? 下列式子求导1.f(x)=x^3-3x^2+3x-22.g(x)=-3x^3+5x^2-4x+113.u(x)=-x^3+27x+74.h(x)=42-45x-3x^2+3x^35.f(x)=Lnx+x6.g(x)=x/(2+x^2) x+(2-x)+(4-x)=50怎么解 一元二次方程解答!x（5x+4）=5x+44x^2-45=31x-3x^2+22x-24=0(x+8)(x+1)= -12(3x+2)(x+3)=x+14 x+2x+3x+4x+5x+6x+7x+8x+9x=9x-8x-7x-6x-5x-4x-3x-2x-x.x等于多少? 20%=(X+4)/(50+X)x=?(50g*8%)+(x*40%)=(50+x)20%，x=？