若y=cosx 2psinx

N={(1,1)},M={(x,y)|y-3=x-2},即M={(x,y)|y-x-1=0},CIM即为除直线外的所有的（x,y),CIN即为除（1,1）外的（x,y),所以(CIM)∩（(CIM)）

根据题意得：x2−4≥04−x2≥0x−2≠0，解得：x=-2，则y=4，故x2+y=8，则x2+y的立方根是2．

设(x+y-z)/z=(x-y+z)/y=(-x+y+z)/x=k则（1）x+y-z=kz（2）x-y+z=ky（3）-x+y+z=kx（1）+（2）+（3）得x+y+z=k(x+y+z)∴k=1时,

Dx^y+x^-y=2根号2===>(x^y+x^-y)^2=8===>x^2y+x^-2y+2=8===>x^2y+x^-2y=6(x^y-x^-y)^2=x^2y+x^-2y-2=6-2=4==>

(2x-y)(2x+y)+(2x-y)(y-4x)+2y(y-3x)=4x^2-y^2+2xy-8x^2-y^2+4xy+2y^2-6xy=-4x^2=-4(-1/4)^2=-1/4

3x=4Y.X/Y=4/3,x-y)/y=(X/Y)-1=1/3,（3x+2y)/(2x+3y)=(4Y+2y)/(8/3y+3y)=18/17（因为3x=4Y,2x=8/3y）再问：若3X-4Y=0

原式=（X²+Y²-X²+2XY-Y²+2XY-2Y²）/4Y=（4XY-2Y²）/4Y=（2X-Y）/2=0

y的三次方-3y平方+y-2=y（y的平方-y-1）-2（y的平方-y-1）-4=-4

因为X-Y=1所以原式=x*1+y*（-1）+2013=x-y+2013=1+2013=2014

(x*x+y*y)(x*x+y*y)-4x*x*y*y=(x^4-2x^2y^2+y^4)=(x^2-y^2)^2=0x^2=y^2x/y=±1(x*x+5xy+y*y)/(x*x+2xy+y*y)=

7：3

3x-5y=0,则x+y/x=（8/5）,x-y/y=（2/3）,2x-3y/2x+3y=(1/19)因为3x-5y=0所以3x=5y设x=5,y=3,可以解得3x-5y=0,则x+y/x=（8/5）

x+y=1x-y=2(x+2y)(x-2y)-(2x-y)(-y-2x)=(x+2y)(x-2y)+(2x-y)(y+2x)=x²-4y²+4x²-y²=5x&

若x-y/x+y=5则x-y=5(x+y)所以求x-y/2x+2y+5x+5y/3x-3y=5(x+y)/[2(x+y)]+5(x+y)/3(x-y)=5/2+5(x+y)/[3*5(x+y)]=5/

7y(x-3y)²-2(3y-x)³=7y(x-3y)²+2(x-3y)³=(x-3y)²[7y+2(x-3y)=(x-3y)²(7y+2X

若(x-y)/(x+y)=3那么x-y=3(x+y)x-y=3x+3y故x=-2y所以(x+2y)/(6x-7y)=(-2y+2y)/(6*(-2y)-7y)=0如果不懂,请Hi我,祝学习愉快!

先化简原式=（2X-Y)(2X+Y)+(2X-Y)(Y-4X)+2Y(Y-3X)=4x"2-y"2-8x"2-y"2+6xy+2y"2-6xy=-4x"2=-1/4可以确定上式得值

若|*+5|+|y-1|=0,则*+Y=-4绝对值小于4的所有整数的和为0若|*|=5,|y|=3,则|*+y|=8或-2如果哦某一时刻的温度增加8度后为-2度,那么这一时刻的温度为（-10）度

(y^2-12)/y

∵|x+2y-1|+y²+4y+4=0∴|x+2y-1|+(y+2)²=0∴x=5,y=-2(2x-y)²-2(2x-y)(x+2y)+(x+2y)²=[(2x