Quote:
Originally Posted by moeloubani
I don't think you guys understand that 2(9+3) is the exact same thing as 2 * (9+3)
There is no rule that says you would do implied first. Since there is no concrete rule then you just do it from left to right. So written like it is, the answer is 288.
http://mathforum.org/library/drmath/view/54341.html
A math phd spelling it out for you guys.
The way it is written you do things in the order they appear.
Therefore answer is 288. |
Even Doctor Peterson, in your cited example, lends credibility to the implied multiplication rule and states that the rule is used in some texts. The Math Phd does not merely support your side of things.
Bottom line: You can't "drop" parentheses willy nilly, you have to complete the implied multiplication first.
The date of your quoted example is also telling - (
1999). Standards in this year of 2011 state that implied multiplication is possible through parentheses which takes priority over other functions. When you have a number outside parentheses it implies that you multiply the outside by the value of the inside.
So when you simplify 48÷2(9+3) you get 48÷2(12) not 48÷2*12 because you haven't multiplied 2 by (9+3), now (12), yet. Keep your parentheses! Only drop them after completing the implied multiplication. 48÷2(12) = 48÷24 = 2