![\"\"](\"/images/stars/stars-13.gif\")
You can put this solution on YOUR website!
\n" ); document.write( "The algebraic solution outlined by the other tutor is certainly valid; you should know how to solve problems like this using that method.
\n" ); document.write( "But it is also good to be able to understand what is happening in the problem so you can see how to get the solution informally, by logical reasoning.
\n" ); document.write( "For this type of problem, where you are given the sum and difference of two numbers, think of a number line. You start at one of the two numbers; to get the sum of the two numbers, you go one direction on the number line from the first number; to get the difference, you go the opposite direction.
\n" ); document.write( "That means the first number is halfway between the sum and difference of the two numbers -- i.e., it is the average of the sum and difference.
\n" ); document.write( "So in this example, a quick way to the solution is to see one number as