How do you simplify #13 - 5 + 1 # using PEMDAS?

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Answer 1 · 2018-03-31T06:58:33

#9#

The problem arises in identifying the adds and the subtracts!

The question does NOT mean #13-(5+1)#, where the addition is seen as #5+1#

Remember that a sign belongs to the number on the right.

What we actually have is

#(+13) +(-5) +(+1)#

I prefer to have students rearranging the terms first, with the ADDS at the beginning and the SUBTRACTS at the end.

#13+1-5 = 9#

Or just work from left to right.

#color(blue)(13-5)+1#

#=color(blue)(8)+1#

#=9#