What are parenthesis?

There is no operator given an in such cases it is often taken to be multiplication eg ab = a*b Thus 2*(-4)*(3) = -24

Yes you can. It looks like this: (()This is called "nesting" parentheses. It is applicable to both language e.g. John saw the boy (who was standing on the bridge (Wikfield's Bridge)) take the money....

2n2y2(2n3)(3y3)

After the parenthesis, ie: Jane (a timid girl) walked slowly to school. orJane walked slowly to school (a big high school).when it is the last part of the sentence you place it inside Jane walked...

(4x ^2 + 3) + (3x ^2 + 8) = ( 4x^2 + 3x^2 ) + (3+8) = 7x^2 + 11