document.write( "Question 419240: solve the following system of equations\r
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document.write( "x+3y=4 (1)
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document.write( "x=5-3y (2)\r
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document.write( "the solution is?? or there is no solution? \n" );
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Algebra.Com's Answer #293226 by duckness73(47)![]() ![]() You can put this solution on YOUR website! Lets look carefully at these equations:\r \n" ); document.write( "\n" ); document.write( "x + 3y = 4 \n" ); document.write( "x = 5 - 3y\r \n" ); document.write( "\n" ); document.write( "If we substitute the expression of x from the second equation into the first, we have:\r \n" ); document.write( "\n" ); document.write( "(5 - 3y) + 3y = 4\r \n" ); document.write( "\n" ); document.write( "Simplifying the equation and collecting like terms we have: \n" ); document.write( "5 - 3y + 3y = 4 or \n" ); document.write( "5 = 4\r \n" ); document.write( "\n" ); document.write( "Since this clearly is a false statement, the system of equations has NO solution.\r \n" ); document.write( "\n" ); document.write( "Another way to look at this problem is to get both equations into slope-intercept form y = mx + b. We have\r \n" ); document.write( "\n" ); document.write( "y = -(1/3)x + (4/3) \n" ); document.write( "y = -(1/3)x + (5/3)\r \n" ); document.write( "\n" ); document.write( "In this case, the slope of each equation is -(1/3). This means that the lines are either parallel or they are the same line. Because the intercept is different ((4/3) in the first equation and (5/3) in the second equation)) the lines are NOT the same line, therefore they must be parallel. Systems of equations representing parallel lines have no solution. \n" ); document.write( " \n" ); document.write( " |