Replace with or replace for?

Question

Sentence: I want to replace algebra (with/for) trigonometry.

If I use the word with, then does that's an I want trigonometry and not algebra? If I use the word for, then does that mean I want algebra and not trigonometry?

Any rules?

Answer 1

with = not algebra

for = not trig

However, "for" version is a little awkward.

"I want to take algebra instead of trigonometry" would be better.