how do i translate this into a formula

if d47 equals blank then blank else if d48 equals blank then
if (today - d47) 89 then e47 else 0, if d48 is not blank then if(d48 -
d47)89 then e47 else 0

basically if there is no date in d47 then 0
if there is a date in d47 and no date in d48 then i want
it to return the value of e47 if the difference between d47 and today is
greater than 89 days if its less than 89 days then i want it to return 0. if
d48 does has a date then if the difference between d48 and d47 is greater
than 89 than return the value of e47 otherwise 0.