3x-5=2(2x+5)

Question

I have no idea for what the answer is to this question because the teachers wont teach it right or good enough for me.

Answer 1

Hi Kaela, let me see if I can help...

 

Let's start at the beginning:

 

3x - 5 = 2(2x + 5)

 

First, we want to distribute the 2 through the entire parentheses:

 

3x - 5 = 2*2x + 2*5

3x - 5 = 4x + 10

 

Now, we subtract 4x from both sides:

 

 

  3x - 5 = 4x + 10

-4x         -4x

-----      -----

  -x - 5 = 10

 

Now, we add 5 to both sides:

 

-x - 5 = 10

    +5    +5

    ----  ----

-x = 15

 

To solve for "x" (not -x) we need to multiply both sides of the equation by a negative:

 

x = -15

 

If any of these steps are confusing or you would like more explanation, let me know.

 

Hope this helps!

 

Dr. B