SOLUTION: perform the indicated operation and simplify if possible -20/21.7/30.(-11)

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Question 549990: perform the indicated operation and simplify if possible
-20/21.7/30.(-11)
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
If I believe those dots are decimal points, a dot after 30 suggests there is a missing decimal part that was inadvertently left out.
However, I believe those were probably middle dots, indicating multiplication, that did not end up appearing as intended.
According to the rules of order of operations, when you have just multiplications and divisions, you just do one operation at a time, in order from left to right.
-20/21%2A7/30%2A%28-11%29=-(%2820%2F21%29%2A7)/30%2A%28-11%29
At this point we can simplify something.
-(%2820%2F21%29%2A7)/30%2A%28-11%29 = -%2820%2A7%2F21%29/30%2A%28-11%29 = -%2820%2F3%29/30%2A%28-11%29
From there on,
-%2820%2F3%29/30%2A%28-11%29=-%2820%2F%283%2A30%29%29(-11)=-%282%2F9%29(-11)=22/9
Multiplication has no priority over division, despite what PEMDAS suggests. In the acronym, M and D should really be one on top of another.