Giúp mik bài này với, mik đang cần gấp

1.

a)2/xy:(1/x-1/y)²=2/xy:(y-x/xy)²=2/xy:(y²-2xy+x²/x²y²)=2/xy.(x²y²/y²-2xy+x²)=2xy/y²-2xy+x²

b)(1-2/x+1):[1-(x²-2/x²-1)]=(x+1-2/x+1):[(x²-1-x²+2)/x²-1]=(x-1/x+1).(-x²+1)=-(x-1)²

c) (5x-2/x²-10x+5x-2/x²+10x).(x²-100/x²+4)

=[5x-2/x(x-10)+5x-2/x(x+10)].[(x-10)(x+10)/x²+4]

=[(5x-2)(x+10)+(5x-2)(x-10)/x(x+10)(x+10)].[(x-10)(x+10)/x²+4]

=[(5x-2)(x+10+x-10)/x(x+10)(x+10)].[(x-10)(x+10)/x²+4]

=[(5x-2)2x/x(x+10)(x+10)].[(x-10)(x+10)/x²+4]

=10x-4/x²+4

d)Còn câu d có j chiều mk làm cho nhé, h mk đi ăn cơm đã:>