[5x 14y=2419x-21y=17

是这样的：x^5+x^4=x^3(x^2+x)=(x^2+x)[(x^3-1)+1]=(x^2+x)(x^3-1)+x^2+x=[x(x+1)(x-1)](x^2+x+1)+x^2+x=(x^3-x)

这是两道题吗?1、两边同时乘(x-1)(x-2)(x-3）答案是x1=-1,x2=22、分母因式分解分别为(x-7)(2x+3)和(x-5)(x-7)然后同时乘(x-5)(x-7)(2x+3)答案是x

(x^2+7x+5)^2-3x^2-21x=19原方程可化为(x²+7x+5)²-3(x²+7x+5)-4=0所以(x²+7x+5-4)(x²+7x+

x/(2x^2-11x-21)=(x+7)/(x^2-12x+35)x/(2x+3)(x-7)=(x+7)/(x-5)(x-7)x/(2x+3)=(x+7)/(x-5)x(x-5)=(x+7)(2x+

x(1+2+...+9)=x(9-8-7-...-1)x=0记得采纳啊

2x+3x+4x+5x+x+6x+7x=10028x=100x=100/28x=25/7

CaCO3+2HCl===CaCl2+H2O+CO2100731114426.0350*0.3828.8911.45最后的溶液为CaCl2水溶液,质量分数是28.89/(26.03+50-11.45)

35(X-2)+15(5X-6)=(22X-51)+21(3X-4)35X-70+75X-90=22X-51+63X-8435X+75X-22X-63X=-51-84+70+9025X=25X=1再问

x/(x-2)=2x/(x-3)+(1-x)/(x-5x+6)x/(x-2)=2x/(x-3)+(1-x)/(x-2)(x-3)x(x-3)/(x-2)(x-3)=2x(x-2)/(x-2)(x-3)

题目应是1/(x^2+x﹚+1/(x^2+3x+2﹚+1/(x^2+5x+6﹚+1/(x^2+7x+12﹚=4/211/x(x+1﹚+1/(x+1)(x+2)+1/(x+2)(x+3)+1/(x+3)

首先(x^2-2x+1)恒大于零,所以可以乘到不等式右边,然后化简最后可得-8

第一题两边同乘于(y+2)(y-2),得2=y-2-y^2+4y^2-y=0y(y-1)=0解之得：y=0或y=1第二题两边同乘于(x+2)(X-2)化简得15-2(x+2)=x^2-4x^2+2x-

1、x-3x-8=21得x=-29/2；转换为x平方-120x+5=0得x=±根号（3595）+602、x+25%x=20X3x=60除以1.25x=483、4x+10=150x=(150-10)/4

(5x-96)/(x-19)+(x-8)/(x-9)=(4x-19)/(x-6)+(2x-21)/(x-8)5-1/(x-19)+1+1/(x-9)=4+5/(x-6)+2-5/(x-8)即1/(x-

x+5分之2x=211又5分之2x=21x=21÷5分之7x=15x+20%x=9.6120%x=9.6x=9.6÷120%x=8

=x^2+10x-24+x^2+15x+56-x^2+5x+50=x^2+30x+82=4+60+82=146其实,不化简,直接代入=14*0+9*10+7*8=0+90+56=146也很简单

#includesintjiesheng(intn)//用于计算阶乘如：3!{if(n=1)rerunn;returnn*hh(n-1)}doubledigui(intn,intx)//用以计算y=x

35(x-2)-15(5x-6)=(22x-63)-21(3x-4)35x-70-75x+90=22x-63-63x+84-45x+20=-41x+2145x-41x=20-214x=-1x=-1/4

5x²-11x-21=05x²-11x=215[x²-11x/5+(11/10)²]=21+5×(11/10)²(x-11/10)²=541

乘以21得21x+15x=836x=8x=2/9