The set of all possible x values is called the

Driving 75 mph, it takes alicia 2 hours to reach the airport to go on a vacation. it then takes her 4 hours to get to her destination with the jet traveling at a speed of 400 mph. how many miles does alicia travel to get to her destination?

I’m stuck on this equation, anyone got the answer?

Scenario: susan wants to make 2 square flags to sell at a crafts fair. the fabric she wants to buy is 3 meters wide. she doesn't want any fabric left over. what's the least amount of fabric she should buy? question: which equation will susan solve her problem? note: let x represent the length of 1 side of the flag. options: 1) 3x^2 -2x =0 2) 2x^2 =3x 3) 2 * 2 = 2 * 2 4) 6 +2x = 2(4x)