【5道数学题，谢谢！】

(-2xy^2)^2除以xy^3/x-y乘1/2(y-x)^2
=4x^2y^4*(x-y)/(xy^3)*1/2(x-y)^2
=2xy/(x-y)

(3-x)/(2x-4)除以(x+2-5)/(x-2)
=(3-x)/[2(x-2)]*(x-2)/(x-3)

=-1/2

(a-4)/a除以[(a+2)/(a^2-2a) -( a-1)/(a^2-4a+4)]

=[(a-4)/a]/[(a+2)/a(a-2)-(a-1)/(a-2)^2]

=[(a-4)/a]/{[(a+2)(a-2)-a(a-1)]/a(a-2)^2}

=[(a-4)/a]/[(a^2-4-a^2+a)/a(a-2)^2]

=[(a-4)/a]/[(a-4)/a(a-2)^2]

=(a-4)/a*a(a-2)^2/(a-4)

=(a-2)^2

x/(x-3)=2+ 3/(3-x)

x/(x-3)+3/(x-3)=2

(x+3)/(x-3)=2

x+3=2x-6

x=9

1/(x-2)=(1-x)/(2-x) -3

1/(x-2)+(1-x)/(x-2)=-3

(1+1-x)/(x-2)=-3

2-x=-3(x-2)

2-x=-3x+6

x=2

请问 阁下的问题是什么 是要求我数数里面X的个数还是颜色？

题目描述的不清楚.
哪些跟哪些是一行完全看不出来.
这类问题的解决办法都是
化简->合并同类项->得出结果