document.write( "Question 165142: find two numbers such that five times the larger plud three times the smaller is 47 and four times the larger minus twice the smaller is 20. \n" ); document.write( "
Algebra.Com's Answer #121721 by nerdybill(7384)![]() ![]() You can put this solution on YOUR website! Let S = smaller number \n" ); document.write( "and \n" ); document.write( "L = larger number \n" ); document.write( ". \n" ); document.write( "Since we have two unknowns, we'll need two equations. \n" ); document.write( ". \n" ); document.write( "Equation 1: \"five times the larger plus three times the smaller is 47\" \n" ); document.write( "5L + 3S = 47 \n" ); document.write( ". \n" ); document.write( "Equation 2: \"four times the larger minus twice the smaller is 20\" \n" ); document.write( "4L - 2S = 20 \n" ); document.write( ". \n" ); document.write( "Using the \"substitution method\", solve equation 2 for S: \n" ); document.write( "4L - 2S = 20 \n" ); document.write( "4L = 2S + 20 \n" ); document.write( "4L-20 = 2S \n" ); document.write( "2L-10 = S \n" ); document.write( ". \n" ); document.write( "Substitute the above into equation 1 and solve for L: \n" ); document.write( "5L + 3S = 47 \n" ); document.write( "5L + 3(2L-10) = 47 \n" ); document.write( "5L + 6L-30 = 47 \n" ); document.write( "11L - 30 = 47 \n" ); document.write( "11L = 77 \n" ); document.write( "L = 7 \n" ); document.write( ". \n" ); document.write( "Finally, plug the above back into equation 2 and solve for S: \n" ); document.write( "4L - 2S = 2 \n" ); document.write( "4(7) - 2S = 2 \n" ); document.write( "28 - S = 1 \n" ); document.write( "28 = S + 1 \n" ); document.write( "27 = S \n" ); document.write( ". \n" ); document.write( "Solution: The two numbers are 7 and 27 \n" ); document.write( " \n" ); document.write( " |