6分之5x 1=8分之9x 1-3分之1-x,求x=-搜答案-搜狗做题网

[(111/9-32/5x17/17)-82/5÷3.6]÷26/25=[(100/9-17/5x24/17)-42/5x10/36]x56/25=[(100/9-24/5)-14/6]x56/25=

4分之3x9分之7+0.75x9分之2=3/4x(7/9+2/9)=3/4x1=3/42.5x1.25x32=2.5x4x(1.25x8)=10x10=10049.5-17.25-2.25=49.5-

∵x²+6x+3=0∴x1+x2=-6x1x2=3x1/x2+x2/x1=(x1+x2)²-2x1x2/x1x2=10

x1+x2=5;x1x2=1;(1)x1/x2+x2/x1=(x1²+x2²)/(x1x2)=((x1+x2)²-2x1x2)/(x1x2)=(25-2)/1=23;(2

利用x1+X2=-B/A,x1x2=C/A(1)1/x1+1/x2=(x1+x2)/x1x2=-(-6/2)/(3/2)=-2(2)在菱形ABCD中边长是5,所以有OA^2+OB^2=5^2=25OA

兄弟,真的很简单,但是没有时间给你做你看下韦达定理,全部是基本应用,及两根之和、两根之积的关系,一下就出了.比如第一题,直接通分,第一空-5,第二个-3,第三个是（x1-x2)²=（x1+x

X的平方吧!x1分之x2加x2分之1=x1x2分之x1的平方+x2的平方=x1x2分之（x1+x2)的平方-2x1x2=因为x1+x2=-6x1x2=3所以原式等于3分之30=10

a=5,b=-7,c=-3所以x1+x2=7/5x1x2=-3/5所以x1²+x2²=(x1+x2)²-2x1x2=49/25+6/5=79/251/x1+1/x2=(x

已知x1是方程的解,则2x1²-2x1-5=0===>x1²-x1=5/2=2.5又,x1,x2是方程的两个解,则：x1+x2=1,x1x2=-5/2x1³+3x1

x/4+0.75x=1/82x+0.75=12x=0.25x=0.1254（x+0.2）=1.24x=1.2-0.84x=0.4x=0.15x-1/3=2/315x-1=215x=3x=0.2可以重新

X1+X2=3/2X1*X2=-5/2(1)1/X1+1/X2=(X1+X2)/X1*X2=-3/5(2)x1²+x2²=(X1+X2)²-2*X1*X2=29/4(3)

由韦达定理,得x1+x2=-b/a=5x1*x2=c/a=-61/x1+1/x2=(x1+x2)/(x1*x2)=5/(-6)=-5/6

x2/x1²+x1/x2²=(x1³+x2³)/x1²x2²=(x1+x2)(x1²-x1x2+x2²)/(x1x2)&

1乘1一成不变4分之3三头四臂8分之7七上八下3.4不三不四

提取公因式(x1-x2)原式=(x1-x2)]1-4/x1x2]

X1+X2=-6/2=-3X1*X2=-3/21/X1+1/X2=(X1+X2)/(X1X2)=-3/(-3/2)=2

（1）5（2）19/28(3)13/15(4)1/12再有问题,可以继续问我,好好学习,多看书哇,慢慢自己都会了,加油!

x^2-x-6=0(x-3)(x+2)=0x1>x2所以x1=3,x2=-2(3,9/2)代入抛物线和直线9/2=A*3^2=9AA=1/2(-2,2)代入y=kx+32=-2k+3k=-1/2所以y

2x²+5x-3=0（2X-1)(X+3)=0所以有X1=1/2X2=-3或者X1=-3X2=1/2则|x1-x2|=3.51/x1²+1/x2²=4+1/9=37/9