Help please!! i don’t know geometry

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?

If i have 20$ and i gave 5$ away how much i got

Axel follows these steps to divide 40 by 9: start with 40. 1. divide by 9 and write down the remainder. 2. write a zero after the remainder. 3. repeat steps 1 and 2 until you have a remainder of zero. examine his work, and then complete the statements below.