My Math Forum Algebra what is the actual answer ?

 Algebra Pre-Algebra and Basic Algebra Math Forum

 June 4th, 2019, 03:28 PM #1 Member   Joined: Mar 2019 From: TTF area Posts: 83 Thanks: 1 Algebra what is the actual answer ? $$(a-b)^2=a^2-b^2$$ Which values of a and b show that this is not true?
 June 4th, 2019, 03:59 PM #2 Member     Joined: Oct 2018 From: USA Posts: 63 Thanks: 45 Math Focus: Algebraic Geometry $(a-b)^{2} = a^{2} -2ab + b^{2} = a^{2}-b^{2}$ Subtract $a^{2}$ both sides $-2ab = -2b^{2}$ $a=b$ So just choose any $a$ and $b$ such that $a \neq b$ (edit) and $b \neq 0$ as Romsek mentioned Thanks from topsquark and helpmeddddd Last edited by Greens; June 4th, 2019 at 04:25 PM.
 June 4th, 2019, 04:15 PM #3 Senior Member     Joined: Sep 2015 From: USA Posts: 2,452 Thanks: 1337 $(a-b)^2 = a^2 - 2ab + b^2$ $a^2 - 2ab + b^2 = a^2 - b^2$ $2b^2 = 2ab$ $\text{If$b = 0$this is true$\forall a$}$ $\text{otherwise$b=a$}$ $\text{So the original equation is only true if$b=0 \vee a=b$}$ Thanks from topsquark and helpmeddddd
 June 4th, 2019, 10:06 PM #4 Member   Joined: Mar 2019 From: TTF area Posts: 83 Thanks: 1 What if: $$(a â€“ b)^2= a^2â€“ b^2$$ Which values of a and b show that this is not true? A. a = 1, b = 0 $\hspace{1cm}$ B. a = 1, b = 1 C. a = â€“1, b = â€“1 $\hspace{0.58cm}$ D. a = â€“1, b = 0 E. a = 1, b = â€“1 Thanks for those replies. How about this? Last edited by skipjack; June 5th, 2019 at 08:04 AM.
 June 5th, 2019, 03:53 AM #5 Senior Member   Joined: Mar 2019 From: iran Posts: 308 Thanks: 12 E
 June 5th, 2019, 05:28 AM #6 Senior Member   Joined: Oct 2009 Posts: 796 Thanks: 295 You seriously can't plug in the values and see whether it equals?? Thanks from topsquark

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post mdocka1 Computer Science 1 March 30th, 2017 12:04 AM omoplata Algebra 2 March 7th, 2012 02:15 PM jjjsingha Algebra 1 June 25th, 2008 08:43 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top