Likely a very simple Order of Operations question

[ghostmonkey]

Hello all,
Sorry to post what is probably an incredibly dense question - I'm a 27-year-old going back to school (first time in post-secondary) and I'm struggling greatly with the math component of my course.
Here's the problem I'm given:
81 / [(5) 2 - 16] – 4[(2) 3 - 13]

I am confused as to why there are brackets around single numbers (the 5 and the 2), and even when I ignore the brackets, I'm doubting that I did the order of operations correctly.
Here's the answer I came to:
29
Process:
81/[(5)^2-16]-4[(2)^3-13]
81/[25-16] – 4[8-13].
81/9-4*-5
9 - -20
29

TIA for any help/input - I'm sure I'll be back with more idiotic questions

 

[tkhunny]

There are no "simple" order of operations questions.

If those are the rules you have been given, then you did great.

Note: I would personally avoid EVER putting two operation(or sign) symbols together.

Rather than -4*-5, try -4*(-5).
Rather than 9 - - 20, try 9 - (-20).

 

[JeffM]

You are correct that [MATH](5)^2 \equiv 5^2 \equiv 25[/MATH] and [MATH](2)^3 \equiv 2^3 \equiv 8.[/MATH]
But that is not what you showed in your first line.

[MATH](5) \ 2 \equiv 5 * 2 \equiv 10 \ne 25[/MATH] and [MATH](2) \ 3 \equiv 2 * 3 \equiv 6 \ne 8[/MATH]
What is the actual problem that you were given?

 

[ghostmonkey]

Thank you both so much for the very fast responses!

You are correct that [MATH](5)^2 \equiv 5^2 \equiv 25[/MATH] and [MATH](2)^3 \equiv 2^3 \equiv 8.[/MATH]
But that is not what you showed in your first line.

[MATH](5) \ 2 \equiv 5 * 2 \equiv 10 \ne 25[/MATH] and [MATH](2) \ 3 \equiv 2 * 3 \equiv 6 \ne 8[/MATH]
What is the actual problem that you were given?

I totally messed up typing it the first time - the actual problem was [MATH](5)^2 \equiv 5^2 \equiv 25[/MATH] and [MATH](2)^3 \equiv 2^3 \equiv 8.[/MATH]Math is hard for us artsy emotional types I tell ya ?‍

 

[HallsofIvy]

What you originally wrote:

Here's the problem I'm given:
81 / [(5) 2 - 16] – 4[(2) 3 - 13]

would be 81/[10-16]- 4[6- 13]= 81/6- 4(-7)= 27/2+ 28= (27- 56)/2= -29/2.

 

[JeffM]

Thank you both so much for the very fast responses!



I totally messed up typing it the first time - the actual problem was [MATH](5)^2 \equiv 5^2 \equiv 25[/MATH] and [MATH](2)^3 \equiv 2^3 \equiv 8.[/MATH]Math is hard for us artsy emotional types I tell ya ?‍

Just remind yourself that math is a language. You need to be able to translate from English to math and from math to English. To do that you must learn the grammar of math.