document.write( "Question 4841: Solve the system by the addition method\r
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document.write( "x/3-y/2=-5/6\r
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document.write( "x/5-y/3=-3/5 \n" );
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Algebra.Com's Answer #2352 by rapaljer(4671)![]() ![]() You can put this solution on YOUR website! Let's start by clearing those fractions. The LCD for the first equation is 6, for the second equation is 15, so multiply both sides of these equations by those numbers respectively:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "2x - 3y = -5 First Equation \n" ); document.write( "3x - 5y = -9 Second Equation\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now, eliminate either the x in these equations by getting a common number of 6 for the x coefficients. To do this, you must multiply the first equation by 3 and the second equation by -2. It looks like this:\r \n" ); document.write( "\n" ); document.write( "3(2x - 3y ) = 3*(-5) \n" ); document.write( "-2(3x - 5y ) = -2*(-9)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "6x - 9y = -15 \n" ); document.write( "-6x + 10y = 18\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Add the equations together, and you get: \n" ); document.write( " y = 3\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Substitute y = 3 in the first equation: \n" ); document.write( "2x - 3y = -5 \n" ); document.write( "2x -3(3) = -5 \n" ); document.write( "2x - 9 = -5 Add +9 to each side of the equation: \n" ); document.write( "2x - 9 + 9 = -5 + 9 \n" ); document.write( "2x = 4 \n" ); document.write( "x= 2 \n" ); document.write( " \r \n" ); document.write( "\n" ); document.write( "Check it by substituting both x and y in the second equation (NOTE: To be a valid check, you must substitute into the OTHER equation, not the one you just used!!) \n" ); document.write( "3x - 5y = -9 \n" ); document.write( "3(2) - 5(3) = -9 \n" ); document.write( "6 - 15 = -9\r \n" ); document.write( "\n" ); document.write( "Praise the Lord! It checks!!!\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "R^2 at SCC\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |