document.write( "Question 158188: I'm struggling on 2 algebra problems I have. If you could please help me I would greatly appreaciate it.\r
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document.write( "1) The sum of two numbers is 43. One number plus three times the other number is 65. What are the numbers?\r
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document.write( " x + x = 43\r
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document.write( " x + 3x = 65\r
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document.write( "2) The difference between two numbers is 55. Four times the smaller number plus five times the larger number is 176. What are the numbers?\r
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document.write( " z = smaller number \r
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document.write( " y = larger number\r
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document.write( " x - x = 55\r
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document.write( " 4z + 5y = 76\r
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Algebra.Com's Answer #116560 by nerdybill(7384)![]() ![]() You can put this solution on YOUR website! 1) The sum of two numbers is 43. One number plus three times the other number is 65. What are the numbers? \n" ); document.write( "x + x = 43 \n" ); document.write( "x + 3x = 65 \n" ); document.write( "You can't use the SAME variable to represent the two different numbers! Use another variable: \n" ); document.write( "Let x = one number \n" ); document.write( "and y = second number \n" ); document.write( "then \n" ); document.write( "x + y = 43 (equation 1) \n" ); document.write( "x + 3y = 65 (equation 2) \n" ); document.write( ". \n" ); document.write( "solve equation 1 for y: \n" ); document.write( "x + y = 43 \n" ); document.write( "y = 43 - x \n" ); document.write( ". \n" ); document.write( "Substitute the above into equation 2 and solve for x: \n" ); document.write( "x + 3y = 65 \n" ); document.write( "x + 3(43 - x) = 65 \n" ); document.write( "x + 129 - 3x = 65 \n" ); document.write( "129 - 2x = 65 \n" ); document.write( "129 = 2x+65 \n" ); document.write( "64 = 2x \n" ); document.write( "32 = x \n" ); document.write( ". \n" ); document.write( "Substitute the above into equation 1 and solve for y: \n" ); document.write( "x + y = 43 \n" ); document.write( "32 + y = 43 \n" ); document.write( "y = 11 \n" ); document.write( ". \n" ); document.write( "Solution: the numbers are 11 and 32 \n" ); document.write( ". \n" ); document.write( "2) The difference between two numbers is 55. Four times the smaller number plus five times the larger number is 176. What are the numbers? \n" ); document.write( "z = smaller number \n" ); document.write( "y = larger number \n" ); document.write( "x - x = 55 <<<<--how did you get x? should be y-z=55 \n" ); document.write( "4z + 5y = 76 <<<<--should be 176 \n" ); document.write( ". \n" ); document.write( "Let's start over: \n" ); document.write( "z = smaller number \n" ); document.write( "y = larger number \n" ); document.write( "y - z = 55 \n" ); document.write( "4z + 5y = 176 \n" ); document.write( ". \n" ); document.write( "Solve equation 1 for y: \n" ); document.write( "y - z = 55 \n" ); document.write( "y = z+55 \n" ); document.write( ". \n" ); document.write( "Substitute the above into equation 2 and solve for z: \n" ); document.write( "4z + 5y = 176 \n" ); document.write( "4z + 5(z+55) = 176 \n" ); document.write( "4z + 5z + 275 = 176 \n" ); document.write( "4z + 5z + 275 = 176 \n" ); document.write( "9z + 275 = 176 \n" ); document.write( "9z = -99 \n" ); document.write( "z = -11 \n" ); document.write( ". \n" ); document.write( "Substitute the above into equation 1 and solve for y: \n" ); document.write( "y - z = 55 \n" ); document.write( "y - (-11) = 55 \n" ); document.write( "y+11 = 55 \n" ); document.write( "y = 44 \n" ); document.write( ". \n" ); document.write( "Solution: the two numbers are -11 and 44 \n" ); document.write( " |