Subtract vs Subduct - What's the difference?

In lang=en terms the difference between subtract and subduct

is that subtract is to remove or reduce; especially to reduce a quantity or number while subduct is to move downwards underneath something.

is that subtract is to remove or reduce; especially to reduce a quantity or number while subduct is to push under or below.

(wikipedia subtract)

(en verb)

To remove or reduce; especially to reduce a quantity or number

If you subtract the $100 for gas and bridge toll, it was a fairly inexpensive trip.

* subtraction

(en verb)

To push under or below.

To move downwards underneath something.

(rare) To remove; to deduct; to take away; to disregard.