∑ 1. The set of real numbers can be drawn as a line called “the number line”. The symbols implies and iff are used mostly in Algebra II, and you can take this o… Also used for the Cartesian product of any number of sets and the direct product of any number of mathematical structures. (The expression 10 157 is a scientific notation that means that we multiply by 1 followed by 157 zeros.) n=10/7. In accounting, "n" is used in the equation for compound interest. An exclamation point denotes something called a factorial. i did this one mentally. I just wanna understand what it means and would like a clear and simple answer please and thank you. (2)(1)= 3n! 8n- -4n does not equal 8n-4n 8n- -4n is the same as 8n+4n Denotes the sum of a finite number of terms, which are determined by subscripts and superscripts (which can also be placed below and above), such as in $${\displaystyle \textstyle \sum _{i=1}^{n}i^{2}}$$ or {\displaystyle \textstyle \prod _{0