How do you even do this

If a =6, what is the value of 2a(3b + 5c)?

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?

Given: circle o, cd is diameter, chord ab || cd. arc ab = 74°, find arc ca.