Answer
if you have 18a÷(-6)
solution
18×a/-6
you will use 2 since it can go and it is the lowest number that can go so u will use it
18÷2=9
6÷2=3
since 2 can not go again you will use 3 if three can not go you should use another number.
since it is remaining 9
you will say
9÷3=3
3÷3=1
remember the a up you add it so it will become 3a