$x=(42-4,2.10+76:7,6):(0,01.0,1)$
$x=(42-42+10):\dfrac{1}{1000}$
$x=10.1000=10000$
--------------------
$y=(689,7+0,3):(7,4:0,2-2,2-1,5)$
$y=690:(37-2,2-1,5)$
$y=690:(\dfrac{174}{5}-\dfrac{3}{2})$
$y=690:(\dfrac{348}{10}-\dfrac{15}{10})$
$y=690:\dfrac{333}{10}=690.\dfrac{10}{333}=\dfrac{2300}{11}=20,7$
Từ hai điều trên
$→x>y$
Vậy $x>y$