The error in the possessive construction is that, instead of passenger's, it should be "passengers'". The apostrophe should be after the letter "s" because the noun is in the plural form. The correct sentence would be "Passengers' concerns about cell phone use on planes are justified."
Just watch this video it will help https://www.khanacademy.org/math/algebra/introduction-to-algebra/alg1-manipulating-expressions/v/combining-like-terms-and-the-distributive-property
<span>I do not understand Spanish: is what that means :) hope this helps!</span>
