Problem 1
Source: WOWmath at YouTube: https://www.youtube.com/watch?v=23M6fejDgS0&list=PLBF2BE89798DE6FC3&index=37
Problem 3
Source: WOWmath at YouTube: https://www.youtube.com/watch?v=5Dfi0sTUsCg&list=PLBF2BE89798DE6FC3&index=38
Problem 5
Source: WOWmath at YouTube: https://www.youtube.com/watch?v=1vq917Ux90Q&list=PLBF2BE89798DE6FC3&index=39
Problem 4 Form B
Source: WOWmath at YouTube: https://www.youtube.com/watch?v=x8gQ7A4d3kA&list=PLBF2BE89798DE6FC3&index=35
Problem 6 Form B
Source: WOWmath at YouTube: https://www.youtube.com/watch?v=wtCVXmbqs24&list=PLBF2BE89798DE6FC3&index=34