SOLUTION: How do you evaluate 8z+20= -[2z+4]. ( "[" and "]" are suppose to be the straight lines, I just didn't have that on my keyboard

Algebra ->  Absolute-value -> SOLUTION: How do you evaluate 8z+20= -[2z+4]. ( "[" and "]" are suppose to be the straight lines, I just didn't have that on my keyboard       Log On


   

Question 778609: How do you evaluate 8z+20= -[2z+4]. ( "[" and "]" are suppose to be the straight lines, I just didn't have that on my keyboard
Found 2 solutions by psbhowmick, Alan3354:
Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
8z+20=-|2z+4|

This sign |...| is called mod or absolute value i.e. only positive value.

For 2z+4>0 i.e. z>-2
8z+20=-(2z+4)
8z+20=-2z-4
10z=-24
z=-2.4
But since z>-2 so z cannot be equal to -2.4.

For 2z+4<0 i.e. z<-2
8z+20=(2z+4)
6z = -16
z = -16/6=-8/3=-2.67

So the answer is -2.67.

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Look for Shift \ to give |