document.write( "Question 385320: solve
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document.write( "x+4y=19
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document.write( "5x+y+0\r
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document.write( "solve
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document.write( "a-b=25
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document.write( "3a+4b=4 \n" );
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Algebra.Com's Answer #272616 by texttutoring(324)![]() ![]() You can put this solution on YOUR website! x+4y=19 \n" ); document.write( "5x+y+0\r \n" ); document.write( "\n" ); document.write( "Let's solve this one by elimination method. Multiply the second equation by 4, then subtract it from the first equation:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x+4y = 19 \n" ); document.write( "20x +4y = 0 \n" ); document.write( "----------- \n" ); document.write( "-19x = 19\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "x= -1\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Plug this value into either equation to find y:\r \n" ); document.write( "\n" ); document.write( "5x+y = 0 \n" ); document.write( "5(-1) + y = 0 \n" ); document.write( "-5 + y = 0 \n" ); document.write( "y = 5\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So the solution is (-1,5) or x=-1, y=5.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Second question is weird because it has no nice answers. Are you supposed to write your answers as fractions or as decimals? I did it with fractions:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "a-b=25 \n" ); document.write( "3a+4b=4\r \n" ); document.write( "\n" ); document.write( "Multiply the first equation by 3, then subtract.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3a - 3b = 75 \n" ); document.write( "3a + 4b = 4 \n" ); document.write( "-------------- \n" ); document.write( "0 - 7b = 71\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "b = -71/7\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Plug this into either equation to find a:\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "3a - 3(-71/7) = 75 \n" ); document.write( "3a + 213/7 = 75 \n" ); document.write( "3a = 75- 213/7 \n" ); document.write( "3a = 312/7 \n" ); document.write( "a = 312/21 \n" ); document.write( "a = 104/7 \n" ); document.write( " |