How can the issue of overwriting variables $b and $d be resolved in the provided PHP code snippet?

The issue of overwriting variables $b and $d can be resolved by using separate variables for each calculation. This can be achieved by creating new variables $sum1 and $sum2 to store the results of the respective calculations, rather than reusing $b and $d. By doing so, the original values of $b and $d will not be overwritten.

$a = 5;
$b = 10;
$c = 3;
$d = 7;

$sum1 = $a + $b;
$sum2 = $c + $d;

echo "Sum of a and b: " . $sum1 . "\n";
echo "Sum of c and d: " . $sum2 . "\n";