Where does (2 + √π)y come from in this algebra step?

  • Context: High School 
  • Thread starter Thread starter powp
  • Start date Start date
  • Tags Tags
    Book Text Text book
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 3K views
powp
Messages
91
Reaction score
0
Hello

I am doing this problem in my textbook and I am not sure what is happing in this one step.

[tex]2y = 360 \sqrt{\pi} - \sqrt{\pi}y[/tex]

Trying to solve for y and this is what they show as the next step

[tex](2 + \sqrt{\pi})y = 360 \sqrt{\pi}[/tex]

Where does this [tex](2 + \sqrt{\pi})[/tex] come from?? where did the other y go and the [tex]-\sqrt{\pi}[/tex]?
 
Mathematics news on Phys.org
The [tex](2 + \sqrt{\pi})y[/tex] came from adding [tex]\sqrt{\pi}y[/tex] to both sides and then factoring out a y from the left hand side. Have you not learned about collecting terms??

[tex]2y = 360 \sqrt{\pi} - \sqrt{\pi}y[/tex]

[tex]2y + \sqrt{\pi}y = 360\sqrt{\pi} + \sqrt{\pi}y - \sqrt{\pi}y[/tex]

[tex](2y + \sqrt{\pi})y = 360\sqrt{\pi}[/tex]
 
Last edited:
They added [tex]\sqrt{\pi}y[/tex] to both sides.

Now on the left side of the equation we get [tex]2y + \sqrt{\pi}y[/tex]

and on the right we get [tex]360\sqrt{\pi}[/tex]

Now on the left side, they factored out the y so you can solve for it.

[tex]2y + \sqrt{\pi}y = y(2 + \sqrt{\pi})[/tex]

Now putting all of this info together we get

[tex](2 + \sqrt{\pi})y = 360 \sqrt{\pi}[/tex]

and [tex]y = \frac{(360 \sqrt{\pi})}{(2 + \sqrt{\pi})}[/tex]

Jameson
 
Last edited by a moderator: