document.write( "Question 312323: The sum of an integer and three times another integer is 18. Determine the value of the two integers if their product is a maximum. Thanks!\r
\n" ); document.write( "\n" ); document.write( "What I have so far:\r
\n" ); document.write( "\n" ); document.write( "x + 3y = 18
\n" ); document.write( "x = 18 - 3y\r
\n" ); document.write( "\n" ); document.write( "Product = xy = y (18-3y) \n" ); document.write( "

Algebra.Com's Answer #223458 by ankor@dixie-net.com(22740) $\"\"$ $\"About$

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The sum of an integer and three times another integer is 18. Determine the value of the two integers if their product is a maximum. Thanks!
\n" ); document.write( "What I have so far:
\n" ); document.write( "x + 3y = 18
\n" ); document.write( "x = 18 - 3y
\n" ); document.write( "Product = xy = y (18-3y)
\n" ); document.write( "Write it as a quadratic equation
\n" ); document.write( "f(y) = -3y^2 + 18y
\n" ); document.write( "Find the axis of symmetry using y = -b/(2a), where a=-3, b=18
\n" ); document.write( "y = $\"%28-18%29%2F%282%2A-3%29\"$
\n" ); document.write( "y = $\"%28-18%29%2F%28-6%29\"$
\n" ); document.write( "y = +3
\n" ); document.write( ":
\n" ); document.write( "Find x
\n" ); document.write( "x = 18-3(3)
\n" ); document.write( "x = 9 \n" ); document.write( "

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