Answer: Explanation below.
Step-by-step explanation: A good question, since working with inequalities and using the same operations as with "=" equations is a bit uncomfortable. I don't have a mathematical proof for this operation, but approach it with a "Why not?" attitude. If 9>6 and 130 > 30, why wouldn't 139>36? There is nothing in the add operation that should upset the basic inequality. I suggest https://www.storyofmathematics.com/inequalities-math for more information.
