The answer to this question is:
01. (+11)
02. (-33)
The positive integers are added directly to the positive integers as in 01 solutions 3+8 gives 11
where else in the 02 solutions both the integers are negative and when negative integers are added to each other it is added but the sign remains negative (-20)+(-13) gives (-33).
The other formulas are:
(+) × (+) = +; (+) ÷ (+) = +
(-) × (-) = +; (-) ÷ (-) = +
(+) × (-) = -; (+) ÷ (-) = -
(-) × (+) = -; (-) ÷ (+) = -