• Please take a moment and update your account profile. If you have an updated account profile with basic information on why you are on Air Warriors it will help other people respond to your posts. How do you update your profile you ask?

    Go here:

    Edit Account Details and Profile

Practicing Math Problems

Nate58XX

New Member
Hi all,

I've been studying math quite a bit lately, as it has been about 7 years since I have done much. I have been using the study guides and resources everyone has mentioned on here. Today I was looking at the ASTB-E practice questions provided by the actual website, and aside from a log question, and the one below, I got the rest right. I might be having a brain lapse on order of operations, but can someone explain to me how the question below equals 20 as demonstrated on the answer key?

-2^-2[(-4-6^0)(5-3^0)]/|-6|-[-(-2)]

Your help would be greatly appreciated. Thanks!

Nate
 

Attachments

  • ASTB-E-Sample-Questions.pdf
    914.4 KB · Views: 77

Renegade One

Well-Known Member
None
Dude...you copied the problem wrong...which totally screwed me up until I checked the PDF. There is no "minus 2" in the first exponent. It should be:

- 2^2[(-4-6^0)(5-3^0)]
|-6|-[-(-2)]

Then, use PEMDAS and simplify to:

Do the stuff inside the brackets/parens first:
[(-4-6^0)(5-3^0)] equals (minus 4 minus 1)(5 minus 1) which reads [(-5)(4)] which equals [-20]

THEN…this could be a fuck-up…I THINK they mean " - 2^2" equals negative "2 squared" which equals -4 (...NOT "negative 2" squared, which would be 4)

so the top part of the equation is restated as -4 times -20 which equals 80
Then, for the demoninator, |-6|-[-(-2)] is restated a "6 minus 2" which yields 4

80/4 = 20

At least I think so…thanks. I needed to blow those cobwebs off...:cool:


 

zack13usa

Loading...
It took me a minute, but here you go:

-2^-2[(-4-6^0)(5-3^0)]/|-6|-[-(-2)]

-1/4[(-5)(4)]/6-2

-1/4(-20)/4

20/4/4

20
 
Last edited:

Nate58XX

New Member
Dude...you copied the problem wrong...which totally screwed me up until I checked the PDF. There is no "minus 2" in the first exponent. It should be:

- 2^2[(-4-6^0)(5-3^0)]
|-6|-[-(-2)]

Then, use PEMDAS and simplify to:


Do the stuff inside the brackets/parens first:
[(-4-6^0)(5-3^0)] equals (minus 4 minus 1)(5 minus 1) which reads [(-5)(4)] which equals [-20]

THEN…this could be a fuck-up…I THINK they mean " - 2^2" equals negative "2 squared" which equals -4 (...NOT "negative 2" squared, which would be 4)

so the top part of the equation is restated as -4 times -20 which equals 80
Then, for the demoninator, |-6|-[-(-2)] is restated a "6 minus 2" which yields 4

80/4 = 20

At least I think so…thanks. I needed to blow those cobwebs off...:cool:

I definitely know where I screwed up now thanks to you. I am not sure how I got it raised to a negative exponent. You're right on the -4 part. The "-" symbol isn't associated with the number being raised to that power until after that is completed. That helped out quite a bit.
 

ChuckMK23

FERS and TSP contributor!
pilot
Hi all,

I've been studying math quite a bit lately, as it has been about 7 years since I have done much. I have been using the study guides and resources everyone has mentioned on here. Today I was looking at the ASTB-E practice questions provided by the actual website, and aside from a log question, and the one below, I got the rest right. I might be having a brain lapse on order of operations, but can someone explain to me how the question below equals 20 as demonstrated on the answer key?

-2^-2[(-4-6^0)(5-3^0)]/|-6|-[-(-2)]

Your help would be greatly appreciated. Thanks!

Nate

This problem is testing your cognitive reasoning via arithmetic and algebraic order of operations. Kahn academy is a great source of these kind of problems...
 

Nate58XX

New Member
I have been using Khan Academy pretty extensively. I have worked my way through almost all of the Pre-Algebra just to get the foundations set again; now I am about 25% into Algebra 1 and working on probability as well. It has been going well, just need a little explanation now and again.
 

ChuckMK23

FERS and TSP contributor!
pilot
I have been using Khan Academy pretty extensively. I have worked my way through almost all of the Pre-Algebra just to get the foundations set again; now I am about 25% into Algebra 1 and working on probability as well. It has been going well, just need a little explanation now and again.

Good job Nate!

Anyone who cannot cope with mathematics is not fully human. At best, he is a tolerable subhuman who has learned to wear his shoes, bathe, and not make messes in the house.
Robert A. Heinlein
 

Nate58XX

New Member
Thanks! I have to do what I can. I get one chance to take this test and submit my package to the board for lateral move consideration. I can definitely say that I find math far more intriguing than I did in high school and the early years of college.
 
Top