document.write( "Question 1209753: my brother is 7 years younger than me. Twice my age plus 3 times his age is 99.What are our ages?
\n" ); document.write( "Plz use the singapore model method. I have the answer but can not understand how to show the working out using the bar model.\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
Algebra.Com's Answer #850133 by Edwin McCravy(20056)\"\" \"About 
You can put this solution on YOUR website!
\r\n" );
document.write( "The first sentence is:\r\n" );
document.write( "My brother is 7 years younger than ('my age'). It mentions 'my age' second, so:\r\n" );
document.write( "Let this bar be 'my age':\r\n" );
document.write( "\r\n" );
document.write( "And since the brother BRO is 7 years younger, we use a shorter bar for 'BRO's age'.\r\n" );
document.write( "  \r\n" );
document.write( "Now notice that \"my age\" can be partitioned off into 'bro's age' and 7 more,\r\n" );
document.write( "like this:\r\n" );
document.write( "\r\n" );
document.write( "Now we look at the next sentence:\r\n" );
document.write( "Twice my age plus 3 times his age is 99.\r\n" );
document.write( "So we make 2 long bars for 'my age' and 3 short bars for 'bro's age':\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Now let's partition off the bars for 'my age' as we did above:\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "\r\n" );
document.write( "Now we count the BRO's and there are 5 of them.\r\n" );
document.write( "We count the 7's and there are 2 of them, so the equation is\r\n" );
document.write( "\r\n" );
document.write( "                      5 BRO's + 2 7's = 99\r\n" );
document.write( "or                           5B + 2x7 = 99\r\n" );
document.write( "                              5B + 14 = 99\r\n" );
document.write( " Subtract 14 from both sides:      5B = 85\r\n" );
document.write( " Divide both sides by 5:            B = 17\r\n" );
document.write( "\r\n" );
document.write( "BRO is 7 years younger, so 'your age' is 17 + 7 or 24.\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" ); document.write( "
\n" );