灵鹊做题网计算（1）x/x+y-x/x-y （2）a+2+4/a+2 （3）x^2-y^2/xy÷(x+y)
来源：学生作业帮 编辑：灵鹊做题网作业帮 分类：数学作业 时间：2024/04/27 05:15:56
计算（1）x/x+y-x/x-y （2）a+2+4/a+2 （3）x^2-y^2/xy÷(x+y)
（1）x/（x+y)-x/(x-y)
=x(x-y)/(x+y)(x-y)-x(x+y)/(x+y)(x-y)
=(x^2-xy-x^2-xy)/(x+y)(x-y)
=-2xy/(x+y)(x-y)
（2）a+2+4/(a+2 )
=(a+2)(a+2)/(a+2)+4/(a+2)
=(a^2+4a+4+4)/(a+2)
=(a^2+4a+8)/(a+2)
貌似(2)a+2+4/(a-2 )
=(a+2)(a-2)/(a-2)+4/(a-2)
=(a^2-4+4)/(a-2)
=a^2/(a-2)
（3）(x^2-y^2)/xy÷(x+y)
=(x+y)(x-y)/xy*[1/(x+y)]
=(x-y)/xy
=x(x-y)/(x+y)(x-y)-x(x+y)/(x+y)(x-y)
=(x^2-xy-x^2-xy)/(x+y)(x-y)
=-2xy/(x+y)(x-y)
（2）a+2+4/(a+2 )
=(a+2)(a+2)/(a+2)+4/(a+2)
=(a^2+4a+4+4)/(a+2)
=(a^2+4a+8)/(a+2)
貌似(2)a+2+4/(a-2 )
=(a+2)(a-2)/(a-2)+4/(a-2)
=(a^2-4+4)/(a-2)
=a^2/(a-2)
（3）(x^2-y^2)/xy÷(x+y)
=(x+y)(x-y)/xy*[1/(x+y)]
=(x-y)/xy
计算（1）x/x+y-x/x-y （2）a+2+4/a+2 （3）x^2-y^2/xy÷(x+y)
计算4xy+（x-2y）的平方+(x+3y)(3y-x)
计算：3xy[2xy-x（y-2）+x]
x根号x+x根号y/xy-y^2)-（x+根号xy+y/x根号x-y根号）y
计算：(x+y/x-y)÷(xy+x^2)
计算(3x^3y-x^2y+1/2xy)÷(-1/2xy）
（x^2+xy/x-y)/（xy/x-y)计算
（1）x-y/x-2y÷x^2-y^2/x^2-4xy+4y^2
计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2)
计算（1）3x/8y×16y²/27x² （2）（2xy-x²）÷x-2y/xy 2x-6
x-y/x²÷x²-2xy+y²/xy*（xy-x²）
计算3x/8y×16y²/27x² （2xy-x²）÷x-2y/xy 2x-6/x