2 1x^2-2 1x=28

4(x^2-7x+10)-(2x+3)(2x-1)=-214x^2-28x+40-(4x^2-2x+6x-3)=-214x^2-28x+40-4x^2+2x-6x+3+21=0-32x+64=0x=2

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^18+x^15+x^12+x^9+x^6+x^3+1+x^3-1+5-4分解因式把下面的18换成21就是了=(x^18+1)+(x^15+1)+(x^12+1)+(x^9+1)+(x^6+1)+

M大于2小于等于3

这个可以因式分解,呵呵原式=(-x+4)(2x+1)(x-2)(x-1)所以x=4,-0.5,2,1给分吧……对于高次的方程的求解,本人才疏学浅,没有什么特殊的方法,只能去猜根,例如,我先猜出了x=1

1/4X=13X=5210/3X=20/21X=2/70.72X=12.96X=18

把括号拆了5x=5x=1

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

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

x*0.3+x*0.3-21=1/2x0.6x-0.5x=210.1x=21x=210如果本题有什么不明白可以追问,如果满意请点击“选为满意答案”

(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/（2x^2-11x-21）=（x+7）/(x^2-12x+35)x/（2x+3）(x-7)=（x+7）/(x-5)(x-7)约去x-7(显然x=7不是方程的根)x/（2x+3)=（x+7）/(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-21)除以(x-56)=2x-21=2(x-56)x-21=2x-1122x-x=112-21x=91在右上角点击【评价】,然后就可以选择【满意,问题已经完美解决】了.

2(x²-7x)²-21(x²-7x)+10=0[2(x²-7x)-1][(x²-7x)-10]=0(2x²-14x-1)(x-5)(x+2

(12x-10)/21+(7x-9)/20=(2-x)/15+(8x-9)/1220(12x-10)+21(7x-9)=28(2-x)+35(8x-9)240x-200+147x-189=56-28x

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