Abs Value-Thurs with ron

[asth678]

In the abs value video (thurs with ron) Ron said that abs value of a diff =dist btw 2 values
Ia+bI= dist btw a and -b

a=3 b=4
Ia+bI=I3+4I= 7

a and -b= 3 and -4-the dist btw 3 and -4= 7

similarly
a=5 and b=-3
I5 + (-3)I = I5 - 3I = 2

but actual dist btwn 5 and -3 is 8 not 2.

What am i missing? does the rule not apply for negative numbers?

[RonPurewal]

Use the formula that you wrote yourself:

In the abs value video (thurs with ron) Ron said that abs value of a diff =dist btw 2 values
Ia+bI= dist btw a and -b

... so, if a = 5 and b = -3, then this is the distance between 5 and 3 (NOT between 5 and -3).
that distance is 2, as expected.

--

by the way, there's no reason to memorize the thing you wrote up there.
if there's one thing worth memorizing here, it's the fact that
|this - that|
represents the distance between "this" and "that".

then, if you see |a + b|, you can just recognize that it can be rewritten as |a - (-b)|. so then it's the distance between a and -b.
most importantly, though, this is just an example of the formula that's already up there. it's not a new concept or a new formula -- and trying to memorize it as though it were a new thing is just going to make your life harder, not easier.