document.write( "Question 188302: The product of two consecutive numbers is 72. Find the smaller of the numbers \n" ); document.write( "
Algebra.Com's Answer #141168 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
I'm assuming that you want the numbers to be positive.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"The product of two consecutive numbers is 72\" translates to \"x%28x%2B1%29=72\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%28x%2B1%29=72\" Start with the given equation.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%5E2%2Bx=72\" Distribute\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x%5E2%2Bx-72=0\" Subtract 72 from both sides.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Notice we have a quadratic equation in the form of \"ax%5E2%2Bbx%2Bc\" where \"a=1\", \"b=1\", and \"c=-72\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Let's use the quadratic formula to solve for x\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29\" Start with the quadratic formula\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-%281%29+%2B-+sqrt%28+%281%29%5E2-4%281%29%28-72%29+%29%29%2F%282%281%29%29\" Plug in \"a=1\", \"b=1\", and \"c=-72\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1-4%281%29%28-72%29+%29%29%2F%282%281%29%29\" Square \"1\" to get \"1\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1--288+%29%29%2F%282%281%29%29\" Multiply \"4%281%29%28-72%29\" to get \"-288\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+1%2B288+%29%29%2F%282%281%29%29\" Rewrite \"sqrt%281--288%29\" as \"sqrt%281%2B288%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+289+%29%29%2F%282%281%29%29\" Add \"1\" to \"288\" to get \"289\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+sqrt%28+289+%29%29%2F%282%29\" Multiply \"2\" and \"1\" to get \"2\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B-+17%29%2F%282%29\" Take the square root of \"289\" to get \"17\". \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%28-1+%2B+17%29%2F%282%29\" or \"x+=+%28-1+-+17%29%2F%282%29\" Break up the expression. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+%2816%29%2F%282%29\" or \"x+=++%28-18%29%2F%282%29\" Combine like terms. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"x+=+8\" or \"x+=+-9\" Simplify. \r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So the answers are \"x+=+8\" or \"x+=+-9\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "However, we only want the positive numbers. So the only answer is \"x=8\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "This means that the smaller number is 8.
\n" ); document.write( "
\n" );