z is partly constant and partly varies as D when d=1,z=11and when d=2,z=5 find Z when d=4

Answer 1

z = a + bd
Now plug in your numbers
a + 1b = 11
a + 2b = 5
Note that adding b lowered z by 6
You don't even need to know a and b, since when d=4, z(4) will be z(2) - 12.

Answer 2

x-5
4e=u
tt5=;
ww=6