What operation do I use. ​

Hector and alex traded video games. alex gave hector one fourth of his video games in exchange for 6 video games. then he sold 3 video games and gave 2 video games to his brother. alex ended up with 16 video games. how many video games did alex have when he started?

If the perimeter of the garden is 37 ft. the width is x and the length is 15 ft. what is the width of the garden in feet?

Which graph correctly represents the equation  y=−4x−3? guys me iam not trying to fail summer school and will offer 40 points for who ever me with the next 3 problems and will give brainlest