please check my work: simplify 28.43 + (-13.17) + |2.07|

[belle<3]

Evaluate the sum 28.43 + (-13.17) + |2.07|.

28.43 + (-13.17) + |2.07|
28.43 -13.17 + |2.07|
15.6 + |2.07|
= 17.33


I'm "iffy" on absolute value. Are there any rules I should know?

 

[Deleted member 4993]

Re: Just wanted to know if my math was correct.

Evaluate the sum 28.43 + (-13.17) + |2.07|.

28.43 + (-13.17) + |2.07|
28.43 -13.17 + |2.07|

= 15.26 + 2.07

= 17.33

I'm "iffy" on absolute value. Are there any rules I should know?

For this problem - treat the absolute value as if it were a positive number added.

 

[Denis]

Re: Just wanted to know if my math was correct.

28.43 -13.17 + |2.07|
15.6 + |2.07|

C'mon Bella: is 28.43 - 13.17 = 15.6 ?

AND: | n | and |-n | are both simply n : it's that simple :idea:

 

[Loren]

Dennis. Your statement...

"AND: | n | and |-n | are both simply n : it's that simple" is not always true.

What if n = -3.
Plugging that into your statement gives us...

| -3 | and |-(-3) | are both simply -3. That is not true.

 

[Denis]

Well Loren, I'm "trying (not too successfully, I guess" to say that,
IN ALL CASES, || means a positive; or if you remove the "||",
change a negative value to positive.

 

[skeeter]

definition of absolute value ...

|x| = x if x > 0

|x| = -x if x < 0

 

[Denis]

May I state, Sir, that "the absolute value of (-8)" = |-8| = 8,
and invite you to witness the accuracy of above at:
http://www.purplemath.com/modules/absolute.htm

...or other sites as displayed by the search engine at http://www.google.com

 

[stapel]

definition of absolute value ...
|x| = x if x > 0
|x| = -x if x < 0

May I state, Sir, that "the absolute value of (-8)" = |-8| = 8

The two say the same thing!

In the first quote above, the "minus" (as the site in the link explains) means "change the sign". So, applying the definition from the first reply to the example in the second reply, we get:

. . . . .Find the absolute value of x for x = -8.

. . . . .absolute value of x = -8: | x | = | -8 | = 8 = -(-8) = -x

See? :wink:

Eliz.

 

[belle&lt;3]

oh soooorry for the typo! I knew it was 15.26 that's how I got 17.6! :lol:

Thank you for the definition of absolute value that helps.