Let x represent the number of beds per ward.
y represent the number of extra beds
and z represent the number of beds per floor.
In one floor there are 8 wards with x beds on each of them plus a number y of extra beds for emergency.
You can calculate the total number of beds as:
[tex]z=8x+y[/tex]To determine the number of extra beds per floor, write the expression in terms of y:
[tex]y=z-8x[/tex]