1.已知x,y为实数,且y＝(x-1/2)^(1/2)+(1/2-x)^(1/2)+1/2,求5x+|2y-1|-(y^2-(2y)+1)^(1/2)的值2.已知x,y为正数,且(x^(1/2))(x^(1/2)+y^(1/2))＝3(y^(1/2))(x^(1/2)+5(y^(1/2))),求(2x+(xy)^(1/2)+3y)/(x+(xy)^(1/2)-y)的值.3.设x,y是实数,

Question

1.已知x,y为实数,且y＝
(x-1/2)^(1/2)+(1/2-x)^(1/2)+1/2,求 5x+|2y-1|-(y^2-(2y)+1)^(1/2)的值
2.已知x,y为正数,且 (x^(1/2))(x^(1/2)+y^(1/2))＝ 3(y^(1/2))(x^(1/2)+5(y^(1/2))),求 (2x+(xy)^(1/2)+3y)/(x+(xy)^(1/2)-y)的值.
3.设x,y是实数,且 x^2+y^2-(2x)+4y+5＝0,求 (((2^(1/2))*x+((3^(1/2))*y)/2)^2)^(-1/2)
其实上述二分之一次方是二次根式,一共有3题,前面有序号,必须把过程完整的写出来,最佳答案可以得到5经验值
1/2-根号3如何化简？

Answer 1

∵x-1/2≥0,1/2-x≥0∴x=1/2∴y=1/2∴原式=5/2+|1-1|-|1/2-1|=2
题意得 x+(xy)^(1/2)=3(xy)^(1/2)+15y∴(√x)²-2√(xy)-15(√y)²=0∴(√x-5√y)(√x+3√y)=0∴√x-5√y=0∴x=25y
∴原式=（50y+5y+3y)/(25y+5y-y)=58/29=2
题意得 （x-1)²+(y+2)²=0∴x-1=0,y+2=0∴x=1 ,y=-2∴原式=[√2+（-2√3/2)²]^(-1/2)=(3+√2)^(-1/2)=1/√(3+√2)=1/(√2+1)=√2-1