PHP Mortgage Calculator Code, equal and principal, equal to the principal

debx (); functiondebx () {$dkm= 240;//month of loan, 20 is 240 months        $dkTotal= 10000;//Total Loans        $DKNL= 0.0515;//Loan Annual interest rate        $emTotal=$dkTotal*$DKNL/12 *POW(1 +$DKNL/12,$dkm) / (POW(1 +$DKNL/12,$dkm)-1);//Monthly repayment Amount        $lxTotal= 0;//Total Interest         for($i= 0;$i<$dkm;$i++) {              $LX=$dkTotal*$DKNL/12;//Monthly repayment Interest            $em=$emTotal-$LX;//Monthly Repayment principal            Echo"section". ($i+ 1). "Period", "Principal:",$em, "Interest:".$LX, "Total:".$emTotal, "<br/>"; $dkTotal=$dkTotal-$em; $lxTotal=$lxTotal+$LX; }          Echo"Total interest:".$lxTotal; }                  functiondebj () {$dkm= 240;//month of loan, 20 is 240 months        $dkTotal= 10000;//Total Loans        $DKNL= 0.0515;//Loan Annual interest rate                   $em=$dkTotal/$dkm;//repayment principal per month        $lxTotal= 0;//Total Interest         for($i= 0;$i<$dkm;$i++) {              $LX=$dkTotal*$DKNL/12;//Monthly repayment Interest            Echo"section". ($i+ 1). "Period", "Principal:",$em, "Interest:".$LX, "Total:". ($em+$LX), "<br/>"; $dkTotal-=$em; $lxTotal=$lxTotal+$LX; }          Echo"Total interest:".$lxTotal; }                  Exit;

PHP Mortgage Calculator Code, equal and principal, equal to the principal