document.write( "Question 170899: Equations with two variables:\r
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document.write( "Solve for x and y:
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document.write( "8x + 2y = 7
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document.write( "3x - 4y = 5\r
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document.write( "Could you please, give me the answer by parts? I will appreciate if you give me the answer, and understand the questions by parts, because I need to learn who to resolve this type equations?\r
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document.write( "thank you for your help. jessica \n" );
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Algebra.Com's Answer #126173 by ankor@dixie-net.com(22740)![]() ![]() You can put this solution on YOUR website! Solve for x and y: \n" ); document.write( "8x + 2y = 7 \n" ); document.write( "3x - 4y = 5 \n" ); document.write( ": \n" ); document.write( "There are two ways to solve these, elimination and substitution. \n" ); document.write( "Elimination: \n" ); document.write( "You multiply one or both equations so when the equations are added or subtracted, one of the variables is eliminated. Then it is easy to solve for the other variable: \n" ); document.write( ": \n" ); document.write( "Multiply the 1st equation by 2 and you have: \n" ); document.write( "16x + 4y = 14 \n" ); document.write( " 3x - 4y = 5 \n" ); document.write( "----------------Adding will eliminate y: \n" ); document.write( "19x + 0y = 19 \n" ); document.write( "or \n" ); document.write( "19x = 19 \n" ); document.write( "x = \n" ); document.write( "x = 1 \n" ); document.write( ": \n" ); document.write( "Now substitute 1 for x in one of the original equations, we'll use the 1st one. \n" ); document.write( "8(1) + 2y = 7 \n" ); document.write( "8 + 2y = 7 \n" ); document.write( "2y = 7 - 8; subtracted 8 from both sides \n" ); document.write( "2y = -1 \n" ); document.write( "y = \n" ); document.write( ": \n" ); document.write( "Check solutions by substituting both solutions in the 2nd original equation. \n" ); document.write( "3(1) - 4(-1/2) = 5 \n" ); document.write( "3 + 2 = 5; remember minus a minus is a plus \n" ); document.write( ": \n" ); document.write( "Did this help you understand these problems? \n" ); document.write( " |