已知√x-3y |x²-9| (x 3)²=0,求x 1 y 1
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∵实数x,y满足x=√(9-x+2y)+√(3x-6y-27)+5∴9-x+2y≥0,3x-6y-27≥0∴9≥x-2y,x-2y≥9即9≦x-2y≦9∴x-2y=9∴x=√(9-x+2y)+√(3x
4x²+y²-4x-6y+10=0,4x²-4x+1+y²-6y+9=0(2x-1)²+(y-3)²=0x=1/2y=3[2x/3*√(9x
x*x+√3y=√5,y*y+√3x=√5x*x+√3y=y*y+√3xx*x+√3y-y*y-√3x=0(x-y)(x+y)-√3(x-y)=0(x-y)(x+y-√3)=0x≠y,x-y≠0x+y
根据题意有:x²-9=0;x²=9;x=3或x=-3;x-3≠0;x≠3;所以x=-3;y=7/(-3-3)=-7/6;所以5x+6y=-3×5+6×(-7/6)=-15-7=-2
因4x²+y²-4x-6y+10=0所以4x²-4x+1+y²-6y+9=0(2x-1)²+(y-3)²=0所以2x-1=0,y-3=0x=
即(4x²-4x+1)+(y²-6y+9)=0(2x-1)²+(y-3)²=0所以2x-1=y-3=0x=1/2,y=3原式=2x√x+√(xy)-x√x-5√
4x^2+y^2-4x-6y+10=0.配方得(2x-1)^2+(y-3)^2=0,∴2x-1=0,y-3=0,解得x=1/2,y=3.∴(2/3)√(9x)+y^2√(x/y^3)-[x√(1/x)
∵2x-y/x+2y=3∴2(2x-y)/x+2y-9(x+2y)/2x-y+3=2×3-9×1/3+3=6
解题思路:本题主要利用非负性解答。。。。。。。。。。。。解题过程:
X+Y分之X-Y等于3x=-2yX+Y分之2(x-y)减X+Y分之3X+Y=(-x-3y)/(x+y)=1
解题思路:对于这种等式一定可以化成平方相加的形式,这里面要使用到完全平方公式。解题过程:
因为(x-y)/(x+y)=3,则(x+y)/(x-y)=1/3则5(x-y)(x+y)-(x+y)/2(x-y)=5*3-1/(3*2)=15-1/6=89/6
y=√x^2-4+√4-x^2/(x-2)+3x^2-4>=04-x^2>=0x-2≠0解得:x=-2y=39x+8y=9×(-2)+8×3=6
∵x-√x-1=√y+3-y==>x-√x+1/4+y-√y+1/4=9/2==>(√x-1/2)²+(√y-1/2)²=9/2∴设√x-1/2=3cosa/√2,则√y-1/2=
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
前面的式子配方后(x-2)^2+(y-1)^2=0得出x=2,y=1后面的式子看不清楚只要把x,y代进去就可以了
x-2y=3则:x=2y+3代入原式,原式=(4y+6+y-6)/(6y+9-y-9)=5y/5y=1
x/y=3/2则2x=3y带进去就变成6y-9y/(3y+3y)=-1/2y感觉怪怪的.一般都是转换下形式然后带进去这题怎么没一般项--或者直接将x=3y=2带进去
(6x+2y)/(9x-3y)=6(6x/y+2)/(9x/y-3)=6,解得:x/y=5/12(3x+y)^2/(x^2-y^2)=(3x/y+1)^2/((x/y)^2-1)=(81/16)*(2