<?php

error_reporting(-1);

$creditBalance = 40000; 
$percent = 1.03; 
$servicePayment = 1000; 
$monthlyPayment = 5000; 
$paymentTotal = 0; 
$month = 0;
while (($creditBalance * $percent) + $servicePayment > $monthlyPayment) {
 	$month ++;
 	$creditBalance = ( $creditBalance * $percent ) + $servicePayment - $monthlyPayment;
	$paymentTotal = $paymentTotal + $monthlyPayment;
 	echo "{$month} месяц спустя: долг = {$creditBalance} руб, выплачено всего {$paymentTotal} руб. \n";
 	}
$month ++;
$paymentTotal = $paymentTotal + (($creditBalance * $percent) + $servicePayment);
$creditBalance = 0;
echo "{$month} месяц спустя: долг = {$creditBalance} руб, выплачено всего {$paymentTotal} руб. \n";