document.write( "Question 25944: i've got maths homework from my teacher i want to know:why do you need to have a take away sign in front of the equation whilst subtracting terms e.g -y-4y what does the first take away sign mean? \n" ); document.write( "
Algebra.Com's Answer #13953 by Eric Johnston(7)\"\" \"About 
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That is a strange question, since when you add the -y to the -4y you obviously get -5y\r
\n" ); document.write( "\n" ); document.write( "Are you sure is was not -x-4y ?\r
\n" ); document.write( "\n" ); document.write( "It is unusual to put a minus sign in front of the the first variable, so it may be mistake, but it may be intentional. If you have some convenient positive value in the series I would tend put that first to help the user, but sometimes it may be appropriate to put a certain variable first regardless.\r
\n" ); document.write( "\n" ); document.write( "For example, you might do it yourself.\r
\n" ); document.write( "\n" ); document.write( "Say the problem was 3b -a -5d +2c = Answer\r
\n" ); document.write( "\n" ); document.write( "You have a list of values of a, b, c and d and want to write out the equation and work out the answer for each one. It is convenient for you to rearrange the equation thus:\r
\n" ); document.write( "\n" ); document.write( "Answer = -a +3b +2c -5d (it tidies up the sequence a,b,c,d so you are less likely to confuse yourself when substituting in the values)\r
\n" ); document.write( "\n" ); document.write( "Now when you substitute values for a, you get\r
\n" ); document.write( "\n" ); document.write( "a=100 Answer = -100 +3b +2c -5d
\n" ); document.write( "a=-10 Answer = 10 +3b +2c -5d\r
\n" ); document.write( "\n" ); document.write( "Note carefully how when substituting the -10 it turns into +10\r
\n" ); document.write( "\n" ); document.write( "It may be helpful to consider the -a at the front as -1 * a
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