7a. 2 marks Heather is making up a schedule for 20 teams to play in a softball tournament. She has decided to split the teams into 4 divisions of 5 teams each. Each team must play each other once in each division and do not play against teams in other divisions. Find the total number of games she needs to schedule. b. 2 marks Use the binomial theorem to expand (x2 2y)6. 1 16 c. 3 marks Determine the exact value of the 12th term in the expansion of (X2 - 3] without expanding, 1 8 d. 3 marks Determine the term containing x7 in the expansion of (x2 + :J . Full marks awarded for the most efcient method ie. do not expand the entire binomial