Question 247184
a = 3
18 ÷ 2a


Technically speaking you would be correct if you interpreted it as (18/2) * a because the order of arithmetic says multiplication and division are done together from left to right if parentheses don't change the natural order.


The natural order without parentheses is:


exponents and roots first.
then multiplication and division.
then addition and subtraction.


within each level, you process left to right.


this means if you have a multiplication followed by a division, you do the multiplication first, and if you have a division followed by a multiplication, you do the division first.


Select the following link to see one of the tutorials on the web concerning this.


<a href = "http://www.math.com/school/subject2/lessons/S2U1L2GL.html" target = "_blank">http://www.math.com/school/subject2/lessons/S2U1L2GL.html</a>


I tend to think, the way it was written with the other division sign, and the way the 2 and the a were stuck together, that they meant 18 / (2*a), but that would not be technically correct if you follow the rules exactly.


It's a matter of interpretation.


You would not be wrong if you assumed (18/2) * a based on a strict interpretation of the rules.


If the book shows you the answer, you can determine from that.


If not, you can answer with an (if it is this way, then the answer is ...) and (if it is that way, then the answer is ...)


My gut says 18 / (2*a) but the strict interpretation of the rules says (18/2) * a.


I can see why you're confused.