document.write( "Question 597196: The sum of three numbers is 4. The first number minus the second plus 5 times the third is
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document.write( "20. The third plus 5 times the first plus the second is -8. Find the numbers. \n" );
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Algebra.Com's Answer #378084 by math-vortex(648)![]() ![]() You can put this solution on YOUR website! Hi, there--\r \n" ); document.write( "\n" ); document.write( "To solve this problem, we define variables for each number. Then we create a system of three equations in three variables. Finally, we solve the system of equations to find the three numbers. \n" ); document.write( ". \n" ); document.write( "[I] Define the variables.\r \n" ); document.write( "\n" ); document.write( "Call the first number a. \n" ); document.write( "Call the second number b. \n" ); document.write( "Call the third number c. \n" ); document.write( ". \n" ); document.write( ". \n" ); document.write( "[II] Create three equations. \n" ); document.write( ". \n" ); document.write( "The sum of the three numbers is 4. Using algebra, we write this relationship as \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "The first number minus the second plus 5 times the third is \n" ); document.write( "20. In algebra we write this relationship as \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "The third plus 5 times the first plus the second is -8. In algebra we write this relationship as \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Rewrite the third equation to have the variables in alphabetical order. \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( ". \n" ); document.write( "[III] Solve the system of equation. \n" ); document.write( "I'll use the elimination and substitution methods here. You can also use a matrix to easily solve the system. Email me at my gmail address below if you want to see the matrix method, or repost this problem and ask for a matrix method solution. \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Add the 1st and 2nd equations together; solve to give an equation in a and c (NOTE: b+(-b)=0.) \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Subtract \n" ); document.write( " \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Substitute -3 for a in \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Substitute -3 for a and 5 for c in the first equation. Solve for b. \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "According to our algebra, the three numbers are -3, 2, and 5. \n" ); document.write( ". \n" ); document.write( ". \n" ); document.write( "[IV] Check your work. \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "Check! \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "Bingo! \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "Presto! \n" ); document.write( ". \n" ); document.write( "That's it! Feel free to email me via gmail with any questions about the solution. \n" ); document.write( ". \n" ); document.write( "Ms.Figgy \n" ); document.write( "math.in.the.vortex@gmail.com \n" ); document.write( " \n" ); document.write( " |