My Math Forum Positive Exponents

 Algebra Pre-Algebra and Basic Algebra Math Forum

 October 1st, 2011, 01:10 PM #1 Newbie   Joined: May 2011 Posts: 3 Thanks: 0 Positive Exponents Write with only positive exponents. (3x^2 y) (-2x^-2 y) I got -6x^2 y^2 But the teacher got -6y^2 I don't understand how he got that Thanks.
 October 1st, 2011, 01:33 PM #2 Senior Member     Joined: Jul 2010 From: St. Augustine, FL., U.S.A.'s oldest city Posts: 12,170 Thanks: 472 Math Focus: Calculus/ODEs Re: Positive Exponents We are given: $$$3x^2y$$$$-2x^{-2}y$$$ to write using only positive exponents. Multiplying coefficients and like bases, there results: $-6x^{2-2}y^{1+1}=-6x^0y^2=-6y^2$ You incorrectly added exponents on the x terms and got 2 instead of 2 - 2 = 0. This term then becomes 1 and need not be written via the multiplicative identity property, i.e.: $a\cdot1=a$ edit: You also have rewritten the original expression as: $$$3x^2y$$\frac{-2y}{x^2}=\frac{-6x^2y^2}{x^2}$ The $x^2$ factor in both numerator and denominator divide out, leaving: $-6y^2$

 Tags exponents, positive

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Aman Verma Algebra 6 December 28th, 2013 09:55 PM mikeportnoy Algebra 2 December 10th, 2008 07:14 AM TH1 Algebra 3 April 25th, 2008 01:18 PM johnny Algebra 3 November 3rd, 2007 02:28 PM johnny Algebra 2 August 1st, 2007 03:54 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top