14×5+6x=19

8x-16=328x=48x=6x-8分之5x=323x/8=323x=256x=256/37x-（6+3x）=307x-6-3x=304x=36x=94x+（5-3x）=194x+5-3x=19x=

（3x+5)/(x+2)=[(3x+6)-1]/(x+2)=3-1/(x+2)后面都类似化简3-1/(x+2)+3-1/(x+9)=3-1/(x+6)+3-1/(x+5)1/(x+2)+1/(x+9)

设x-y=mx+y=n则6m-2n=143m+n=5解得m=2n=-1即x-y=2x+y=-1解得x=1/2y=-3/2

1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550120x=550x=55/12=4.583

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

3x*x=1+x得6x*x*x+7x*x-5x+2000=3x^2*2x+7x^2-5x+2000=(1+x)2x+7x^2-5x+2000=9x^2-3x+2000=3(3x^2-x)+2000=3

首先整理下7X-15/X-4=14X-31/2X-8,31/2X-15/X=7X-4,两边都乘以2X得14X*X-8X-1=0.然后根据公式X=-b正负根号(§)下b方-4ac得解为X1=(4+§30

1、14(x+6)-6x=8(2x+5)解14x+84-6x=16x+408x=44x=11/22、0.25x+4=30%x+3解0.25x+4=0.3x+30.05x=1x=203、甲数的1/3等于

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)

(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)(X-6)=X-5则(x-5)(x-6)-(x-5)=0则(x-5)(x-6-1)=0则(x-5)(x-7)=0所以x=5或x=7

集合A={x|x^(+6)-ax+a^(+6)-19=0},B={x|x^(+6)-5x+6=0},C={x|{x^(+6)+2x-8=0}若A交B=A并B,求a的值.由A={x|x^2+x-6=0}

(X-4)/(X-5)-(X-5)/(X-6)=(X-7)/(X-8)-(X-8)/(X-9)[(x-4)(x-6)-(x-5)2]/(x-5)(x-6)=[(x-7)(x-9)-(x-8)2]/(x

X-1=3X+32X=-4;X=-2x-3=12-4x5X=15；x=36x-14=5x-10x+1=2-4x5x=1;x=0.2

(1)因为A∩B=A∪B所以A=B={x|x²-5x+6=0}={2,3}由韦达定理有2+3=a,2*3=a²-19所以a=5(2)这一问我感觉表述不清楚(3)若A∩B=A∩C不等

x²-5x+6=0(x-2)(x-3)=0∴B(2,3}x²+2x-8=0(x+4)(x-2)∴C={2,-4}A∩B≠∅,A∩C=∅∴3∈A2∉

B的两个根是2和3C的两个根是2和-4A∩B=A∩C=￠首先A的方程有解且两个交集相等即A和B以及A和C有同一个公共根显然只能是2把x=2代入4-2a+a²-19=0a²-2a-1

原方程可化为3-1/(x-3)+4-1/(x-1)=3-2/(2x-5)+4-2/(2x-3)2/(2x-5)+2/(2x-3)=1/(x-3)+1/(x-1)2/(2x-3)-2/(2x-2)=2/