<?php
// This is my PHP program for variant 07

// Константи
$x1 = 2.6;
$x2 = 2.8;
$a = 3;
$b = 6;

$y1 = pow($x1, 2);         
$y2 = pow($x2, 2);         
$y3 = $y1 + $y2;
$y4 = $y3 - $a;
$y5 = $x1 + $b;
$c = $y4 / $y5;

echo "Результат c = " . round($c, 4) . "\n";
?>