Formula in Notion for project and task due dates

Question

Tasks database has rollup to show the due date for its project, and a task offset number property used to find Suggested Task Due Date using

dateSubtract(prop("Project Due Date"),prop("Task Offset"),"days")

Trying to combine these into just one formula column to make it easier for my team to understand the appropriate due date.

I can do them individually using

if(not empty(prop("Project Due Date")),prop("Project Due Date")

to return the Project Due Date if there is one, and

(dateSubtract(prop("Project Due Date"),prop("Task Offset"),"days"))

to find the Suggested Task Due Date if there is a value in Task Offset. I've been trying to come up with the right nested if statements, or two if(not empty( but maybe that's not the right way to approach it? Thanks in advance!