Solve the equation. |k + 9| = 4

A.
{–13, –5}

B.
{–5, 5}

C.
{–5, 13}

D.
{all real numbers greater than or equal to –13 and less than or equal to –5}

Question

Solve the equation.  |k + 9| = 4
 
 A.
{–13, –5}
 
 B.
{–5, 5}
 
 C.
{–5, 13}
 
 D.
{all real numbers greater than or equal to –13 and less than or equal to –5}

mathstudent55 · Answer

To solve this type of an absolute value equation, just change it into this:

k + 9 = 4 or k + 9 = -4

Now solve each simple equation. Then leave the two answers separated by the word "or."

anonymous · Answer

I'll fan and medal :)

anonymous · Answer

So is it B?

amoodarya · Answer

mathstudent55 give the right answer 
you just simplify them to ...

mathstudent55 · Answer

No.

Did you solve each equation?

Let's do it together.

k + 9 = 4 or k + 9 = -4

In each equation, you see that 9 is being added to k on the left side. To get rid of that 9, we must subtract 9 from both sides in both equations.

   k + 9 = 4    or    k + 9 = -4
       - 9   -9              - 9     -9
--------------------------
   k        = -5  or    k       = -13

anonymous · Answer

Oh, oh oh oh oh!! I get it so its C!?

mathstudent55 · Answer

In the left equation, you get 4 - 9 = -5.
In the right equation, you get -4 - 9 = -13.

C. has POSITIVE 13. We got NEGATIVE 13 and -5.
It's not C.

anonymous · Answer

Oh. wow. Sorry. It's A...

mathstudent55 · Answer

Great. Now you got it.