document.write( "Question 71829: The difference of two numbers is 11. The second is 8 less than 2 times the first. What are two numbers? \n" ); document.write( "
Algebra.Com's Answer #51395 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! Let A represent the first number and B represent the second number. \n" ); document.write( ". \n" ); document.write( "In the problem the first sentence says that difference in these two numbers is 11. Therefore, \n" ); document.write( "you can write the equation for this difference as: \n" ); document.write( ". \n" ); document.write( "A - B = 11 \n" ); document.write( ". \n" ); document.write( "The second sentence says the second number (B) is 8 less than 2 times the first. \n" ); document.write( ". \n" ); document.write( "Two times the first is 2A and 8 less than that is, therefore, 2A - 8. Since this is to \n" ); document.write( "equal the second (B) we can write the equation: \n" ); document.write( ". \n" ); document.write( "2A - 8 = B \n" ); document.write( ". \n" ); document.write( "Notice that from this second equation we have a value for B in terms of A. Let's take \n" ); document.write( "the left side of this equation (that is take 2A - 8) and plug it into our first equation \n" ); document.write( "in place of B. When we do the first equation becomes: \n" ); document.write( ". \n" ); document.write( "A - (2A - 8) = 11 \n" ); document.write( ". \n" ); document.write( "Clear the parens by changing the terms inside to get: \n" ); document.write( ". \n" ); document.write( "A - 2A + 8 = 11 \n" ); document.write( ". \n" ); document.write( "Combine the A terms to get: \n" ); document.write( ". \n" ); document.write( "-A + 8 = 11 \n" ); document.write( ". \n" ); document.write( "Subtract 8 from both sides to get rid of it on the left side: \n" ); document.write( ". \n" ); document.write( "-A = 3 \n" ); document.write( ". \n" ); document.write( "Multiply both sides by -1 and the answer for A is: \n" ); document.write( ". \n" ); document.write( "A = -3 \n" ); document.write( ". \n" ); document.write( "Then you can take this value and substitute is for A in either of our two original \n" ); document.write( "equations. \n" ); document.write( ". \n" ); document.write( "Let's substitute it into the first equation of A - B = 11. When you do you get: \n" ); document.write( ". \n" ); document.write( "-3 - B = 11 \n" ); document.write( ". \n" ); document.write( "Add + 3 to both sides to get rid of the -3 on the left side: \n" ); document.write( ". \n" ); document.write( " -B = 14 \n" ); document.write( ". \n" ); document.write( "And multiply both sides by -1 to solve for B. The result is: \n" ); document.write( ". \n" ); document.write( "B = -14 \n" ); document.write( ". \n" ); document.write( "As a further check is -14 actually 8 less than 2 times (-3). It is and the answer \n" ); document.write( "checks. \n" ); document.write( ". \n" ); document.write( "Hope this helps you to see how to work the problem. The big trick to problems such as \n" ); document.write( "these is to analyze the words and translate them into correct equations. The rest is \n" ); document.write( "straightforward math. \n" ); document.write( " \n" ); document.write( " |