What is the value of r for which \((r-5)^2=(r+2)^2\)?

Joke: Does MATHCOUNTS or does math count?

Sorry....

ANYWAY ON TO THE WORK, I HAVE:

\(r^2 - 10r + 25=r^2+4r+4\)

Then...

Uhmm...

Idk...

Could somebody help me out?

EDIT::

Nvm, solved it!!!

Heres what I got after my first step:

\(r^2 - 10r + 25=r^2+4r+4\)

(subtracted r^2 from both sides)

\(21=14r\)

(like terms to their sides)

\(r=\frac{21}{14}\)

(Simplify)

Could somebody check my work?

tommarvoloriddle Nov 12, 2019

edited by
tommarvoloriddle
Nov 12, 2019

edited by tommarvoloriddle Nov 12, 2019

edited by tommarvoloriddle Nov 12, 2019

edited by tommarvoloriddle Nov 12, 2019

edited by tommarvoloriddle Nov 12, 2019

edited by tommarvoloriddle Nov 12, 2019

edited by tommarvoloriddle Nov 12, 2019

edited by tommarvoloriddle Nov 12, 2019

edited by tommarvoloriddle Nov 12, 2019

#1**+1 **

Hi Tom...riddle

The best way to check question like this is to use Desmos to graph it

Graph

\(y=x^2-10x+25\\ and \\ y=x^2+2x+4\\\)

The x value of where the 2 graphs cross will give the answer

And here is the graph

Melody Nov 12, 2019

#2**+1 **

r^2 +** 2r **+4 ? You need to investigate that part !

Another way to check your work.....Just put your solution into the eqation and see if it works....

ElectricPavlov Nov 12, 2019

#8**0 **

Thanks for picking that up EP

Sorry Tom...riddle about the transfer error.

It was super bad luck that your errror and my different error alligned to give the same answer.

If it hadn't I would have checked both our work to see where the error lay.

Still my checking method is still sound.

Melody
Nov 12, 2019