化简1 2x-2(x-1 3y的平方) (-3 2x 1 3y的平方)

x=1/3y=1/2x-(x+y）+（x+2y)-(x+3y)+...-(x+13y)=6y-13y=-7y=-7/2=-3.5

{2/3x-2/(x+y)[(x+y)/3x-x-y]}/【(x-y)/x】的负二次方={2/3x-[2/(x+y)]*[(x+y)-3x(x+y)]/(3x)}*[x/(x-y)]^2={2/3x-

解原式={2/3X-2/(X+Y)[(X+Y)/3X-(X+Y)]}/(X-Y)*X={2/3X-2/(X+Y)*(X+Y)/3X+2/(X+Y)*(X+Y)}*X/（X+Y）=[2/3X-2/3X+

根据（a+b）^2=a^2+2ab+b^2组合为:X^2+2*2*X+2^2+y^2-2*3*y+3^2=0(x+2)^2+(y-3)^2=0两个因式的和为零,那么只有他们分别为零,即：X+2=0y-

(x+5y-13)^2>=0|2x+3y-12|>=0两个非负数互为相反数,则两个数都是0x+5y-13=0（1）2x+3y-12=0（2）2*（1）-（2）得,10y-3y-26+12=07y=14

56

答案是2.4x-2y/x+3y=(2x-y/x+3y)乘以2=4,4x+12y/2x-y=(x+3y/2x-y)乘以4=1/2x4=2,所以代数式等于4-2=2.

∵x²+y²-4x+2y+5=0x²-4x+4+y²+2y+1=0(x-2)²+(y+1)²=0x-2=0y+1=0∴x=2y=-14x&#

(x+y)-(2x+y/2)-(3x+y/6)-(4x+y/12)-(5x+y/20)-……-(10x+y/90)=x-2x-3x-4x-..-10x+y*(1-1/2-1/6-1/12-..1/90

(x-3y)(x+y)-(x-2y)(x+2y)-(x-y)平方=x²-2xy-3y²-x²+4y²-x²+2xy-y²=(x²-

=-(xy+2)/x×y/(xy+2)=-y/x选A再问：=-(xy+2)/x×y/(xy+2)怎么得的再答：前面部分通分 后面部分也通分 再倒除为乘

1.(-2x^y^)(3x^y^)(-4x^y^)=24x^(1/4-1/2+1/4)y^(-1/3+2/3+2/3)=24x^0y^1=24y2.（6√x)\(3√x√x^5)=18√x^7=18x

(x+3y)²+(2x+y)(x-y)　　=x²+6xy+9y²+2x²-2xy+xy-y²　　=3x²+5xy+8y²ʌ

原式=[(x-y)(x-y)+(x+y)(x-y)]/2x=(x-y)(x-y+x+y)/2x=(x-y)·2x/2x=x-y=3-1.5=1.5

(x-y)^2+12(x-y)+36=(x-y+6)²;很高兴为您解答,skyhunter002为您答疑解惑如果本题有什么不明白可以追问,再问：Guoc过程再答：(x-y)^2+12(x-y

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

x^2+y^2-10x-12y+61=0(x²－10x＋25)＋(y²－12y＋36)=0(x－5)²＋(y－6)²=0因为(x－5)²与(y－6)&

x^2=12x=±2√3y^2=3y=±√3|x-y|=y-x说明y-x≥0即y≥x所以x不可能等于2√3,即x=-2√3若y=-√3,x+y=-3√3若y=√3,x+y=-√3

按题意(5x+2y-12)的平方+13x+2y-61=0中13x+2y-61是指3x+2y-6的绝对值吧,比较合理!由题意要使(5x+2y-12)²+|3x+2y-6|=0,须使：5x+2y

(3x-y)的平方-(2x+y)的平方-5(x-y)=(3x-y+2x+y)(3x-y-2x-y)-5(x-y)=5x(x-2y)-5(x-y)=5x^2-10xy-5x+5y