document.write( "Question 1108943: A picture 9 inches and 8 inches is to be mounted on a piece of matboard so that there is an even amount of mat all around the picture. How wide will the boarder be if the area of the border is 124.
\n" ); document.write( "I did this question for a quiz and I got it wrong. The answer that I got was 9.
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #723949 by ikleyn(52781) $\"\"$ $\"About$

You can put this solution on YOUR website!
.
\n" ); document.write( "

\r\n" );
document.write( "Let x be the width under the question.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Then the outer dimensions are 9+2x and 8+2x.\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "The condition says\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "(9+2x)*(8+2x) - 9*8 = 124    (the difference of the two areas is 124 square inches)\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "16x + 18x  + 4x^2 = 124\r\n" );
document.write( "\r\n" );
document.write( "34x + 4x^2 = 124\r\n" );
document.write( "\r\n" );
document.write( "2x^2 + 17x - 62 = 0\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( " =  = .\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "The only positive root makes sense  x = 2.75 (approximately).\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Answer.  2.75 inches.\r\n" );
document.write( "

\r
\n" ); document.write( "\n" ); document.write( "---------------
\n" ); document.write( "To see other similar solved problems, look into the lessons\r
\n" ); document.write( "\n" ); document.write( "    - Problems on the area and the dimensions of a rectangle surrounded by a strip\r
\n" ); document.write( "\n" ); document.write( "    - Problems on a circular pool and a walkway around it\r
\n" ); document.write( "\n" ); document.write( "in this site.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Also, you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The referred lesson is the part of this online textbook under the topic
\n" ); document.write( "\"Dimensions and the area of rectangles and circles and their elements\".\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "to your archive and use it when it is needed.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "--------------
\n" ); document.write( "Comment from student: Thank you for the help. I have a question though. Wouldn't -62 be put into the quadratic formula as 17^2-4(2)(-62)?
\n" ); document.write( "--------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "My response: 17^2-4(2)(-62) = 17^2 + 4*2*62.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

\n" );