
Algebra PreAlgebra and Basic Algebra Math Forum 
 LinkBack  Thread Tools  Display Modes 
October 16th, 2014, 09:00 PM  #1 
Senior Member Joined: Aug 2014 From: Mars Posts: 101 Thanks: 9  Do I not list simplest form?
I'm getting into quadratic equations and final answers are coming in the form of $\displaystyle 0=8y^2+5y$ instead of $\displaystyle 0=8y+5$ which both come out to be the same answer. So is the author leaving out a process?

October 16th, 2014, 09:17 PM  #2 
Senior Member Joined: Jul 2014 From: भारत Posts: 1,178 Thanks: 230  The latter is the simplification of the former. $\displaystyle \textbf{Transpose } (5y) $ to the left and divide the entire equation by y. Then transpose 5 to the right again, you get the same. Last edited by skipjack; November 22nd, 2014 at 04:02 AM. 
October 16th, 2014, 09:45 PM  #3 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 7,900 Thanks: 1094 Math Focus: Elementary mathematics and beyond 
0 = 8y + 5 effectively omits the solution y = 0.

October 16th, 2014, 10:32 PM  #4 
Senior Member Joined: Aug 2014 From: Mars Posts: 101 Thanks: 9 
I thank you guys for all your help, but I sometimes get the feeling you love trolling everyone. What? What? 
October 17th, 2014, 02:22 AM  #5 
Math Team Joined: May 2013 From: The Astral plane Posts: 1,981 Thanks: 790 Math Focus: Wibbly wobbly timeywimey stuff. 
What trolling? $\displaystyle 8y^2 + 5y = 0$ $\displaystyle y(8y + 5) = 0$ We have the two possibilities: $\displaystyle y = 0 \text{ or } 8y + 5 = 0$ So we have two solutions: $\displaystyle y = 0 \text{ and }y = \frac{5}{8}$ The equation $\displaystyle 8y + 5 = 0$ only has one solution $\displaystyle y = \frac{5}{8}$ So what greg1313 said is perfectly accurate...The difference between the two equations is the existence of the y = 0 solution. How is this trolling? Dan 
October 17th, 2014, 03:11 AM  #6 
Senior Member Joined: Aug 2014 From: Mars Posts: 101 Thanks: 9 
The question is, if I was asked to put this in simplest form, which one would be correct? Neither of your responses said this. Though I do like how it is pointed out that there is a third option of zero on one of the problems. 
October 17th, 2014, 03:22 AM  #7 
Math Team Joined: May 2013 From: The Astral plane Posts: 1,981 Thanks: 790 Math Focus: Wibbly wobbly timeywimey stuff. 
They are both in simplest form as they both have a different set of solutions. They are not the same equation. Dan 

Tags 
form, list, simplest 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
What is the simplest form of this  naufalzhafran  Elementary Math  2  March 9th, 2014 01:20 AM 
12 7/5 in simplest terms  mikeinitaly  Elementary Math  4  October 22nd, 2012 11:52 AM 
Solve by the simplest method  chapsticks  Calculus  2  February 21st, 2012 08:58 PM 
Probably the simplest question of all time.  sterces  Elementary Math  4  September 7th, 2010 12:53 PM 
simplest  rose  Algebra  6  June 23rd, 2010 12:30 AM 