Question 29017
Hi,
Could you please help me solve this absolute value equation?. How do i get rid of the negative sign before the absolute value?

y = - /x-4/

The absolute value of a real number N denoted by |N| is defined as follows
|N|= N if N >=0
|N|= -N if N<0
Examples.1) |3| = 3    
2)|0| = 0       
3) |-3|= -(-3) =+3
4) |12|=12  
5)|-12| =12
6)|-3.8|= +3.8
From the above what we understand is when there are situations dealing in real numbers where we are interested only in a number N and not in its sign then we enclose the number N  in this fashion within two vertical bars  and call it the absolute value of N or the modulus of N.
Applying it to algebra,given a variable u, the absolute value of u  denoted by
|u| is given by |u| = + or - u
If the variable is say (a-b)then its absolute value denoted by |a-b| is given by
|a-b| = +(a-b) or -(a-b)
I hope you have understood these preliminary matters on the definiton of the absolute value of a number.
Now coming to the problem

y = - |x-4|
Multiplying by (-1) through out 
(-y) = |x-4|
That is 
(-y) = +(x-4) or -(x-4) according to the definition we have learnt above.
1)(-y) = +(x-4)implies
0 = x+y-4
That is x+y-4=0
2)(-y) = -(x-4) 
-y = -x+4
x-y-4 = 0
Answer: x+y-4=0 or x-y-4 = 0