Change the margin on the left side of all img elements to 10px.

<html>
<head>
<style>
img {
margin-left:10px;
margin-right:10px;
height:75px;
}
</style>
</head>
<body>
<h1>Top Destinations</h1><img src="https://mimo.app/r/beach.png"><img src="https://mimo.app/r/market.png"><img src="https://mimo.app/r/colosseum.png">

</html>]]>

Make sure to pick margin-left, followed by :, and finally 10px.