In a scenario where Mia possesses x stickers and Liam has y stickers, both x and y being positive integers, the ratio of Mia's stickers to Liam's is 5 to 2. If Mia transfers z stickers to Liam, with z being a positive integer and z < x, and no other changes occur in the quantities of stickers that Mia and Liam hold, the new ratio of Mia's stickers to Liam's stickers will be 5 to 6.

Which of the following equations accurately represents z in terms of x?