<?php
error_reporting(-1);

$credit = 40000;
$percent = 1.03;
$surcharge = 1000;
$total = 0;

$payment = 5000;

for ($i=1; $credit > 0; $i++) {
	$credit = $credit * $percent + $surcharge;
	echo "$i-месяц. Долг на начало $credit. ";
	
	if ($credit < 5000) {
		echo "Осталось совсем немного!";
		$payment = $credit;
	}
	
	$credit -= $payment;
	$total += $payment;
	echo "После выплаты $credit, выплачено $total\n";
	
	
}