document.write( "Question 13774: The sum of two numbers is 15. Three times the first number is equal to 5 times the second number minus 11. What is the equation and what are the two numbers? \n" );
document.write( "solution \n" );
document.write( " let the numbers be X and Y. \n" );
document.write( "then accourding to first condition their sum willbe \n" );
document.write( "x+y= 15 (1) \n" );
document.write( "accourding to second condition we have \n" );
document.write( "3x= 5y-11 (2) \n" );
document.write( "now we can solve the problem by simultaneously solving equations or by putting values of is equation in second\r \n" );
document.write( "\n" );
document.write( "that is \n" );
document.write( "from the first equation \n" );
document.write( "x= 15-y \n" );
document.write( "putting value of x in equation 2 \n" );
document.write( "we get \n" );
document.write( "3(15-y)= 5y-11 \n" );
document.write( "45-3y= 5y-11 \n" );
document.write( "45+11= 5y+3y \n" );
document.write( "56= 8y \n" );
document.write( "or \n" );
document.write( "8y= 56 \n" );
document.write( "y= 56/8 \n" );
document.write( "dividing by 8 on both sides \n" );
document.write( "y= 7 \n" );
document.write( "now for x \n" );
document.write( "put the value of y in equation (1) \n" );
document.write( "that is \n" );
document.write( "x+7= 15 \n" );
document.write( "x= 15-7 \n" );
document.write( "x= 8 \n" );
document.write( "hence x= 8 and y= 9 \n" );
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