Question

5f-(3f+4)=20 The parantheses stand for absolute value

Answer 1

solve for f

Answer 2

can u please help

Answer 3

|3f+4| = 5f-20 so we know |x| = a then \[x= \pm a\]

Answer 4

-1*abs(3f+4)=20-3f
abs(3f+4)=-20+3f

Answer 5

what does abs mean?

Answer 6

absolute value

Answer 7

oh.. so u pretty much distribute it like if it were just a regular parantheses?

Answer 8

no

Answer 9

so \(\bf 5f-|3f+4|=20\)
keep in mind that |whatever|
really means
+1(whatever) AND -1(whatever)
thus you'd get 2 values for "x", then
\(\bf 5f-|3f+4|=20\\ \implies 5f-20 = |3f+4|\\
5f-20 = +1(3f+4) \implies 5f-20 = 3f+4\\
5f-20 = -1(3f+4) \implies 5f-20 = -3f-4\)

Answer 10

im confused on how you reached the third step?

Answer 11

sorry i meant the second step

Answer 12

hmmm which 2nd step?

Answer 13

hurry please i g2g

Answer 14

5f-20= abs 3f +4

Answer 15

-1*abs(3f+4)=20-3f subtracted 3f from both sides to get it on the right
NOTICE:
-abs(3f+4) and -1*abs(3f+4) are same but it's just easier to see that it is multiplied by a negative. It is just shorthand.

we multiply both sides by -1
-1*-1*abs(3f+4) = -1*(-20+3f)

abs(3f+4)=-20+3f


Now as jdoe says

x=±a

same as

3f+4= (-20+3f) and 3f+4= -(-20+3f)

I think that is how it works you have to solve both equations but now you got rid of absolute value sign :)

Answer 16

\(\bf 5f-|3f+4|=20 \implies 5f-20 = |3f+4| \ \ ?\)

Answer 17

yes that one

Answer 18

ohh, all I did was isolate the absolute expression, so I can do the +1/-1 part with less clutter

Answer 19

oh ok so the two answers are both the same just negative and positive?

Answer 20

yes, absolute value expressions give you 2 values

Answer 21

so x will have 2 values

Answer 22

so this is for every absolute value equation? same solution just negative and positive

Answer 23

the expression turns negative and positive, yes

Answer 24

alright thanks ;D how do I give a medal?

Answer 25

heheh, no need heh

Answer 26

lol i figured u dont even have a profile pic. thanks again

Answer 27

well, yes I was going to upload this pic of mine http://www.fabioinc.com/FABIO_MODEL%20folder/Fabio_M_blueShirt_gap_web.jpg but I figure it might create a riot and a lawsuit from gap inc. so tis ok =)

Answer 28

ok ok, so it's not my pic =)