Please help with all, I’ll mark brainliest as long as you tell me how you got that answer.

For the rule of 78, for a 12-month period, the last term in the sequence is 12 and the series sums to 78. for an 10 month period, the last term is and the series sum is . for a 15 month period, the last term is and the series sum is . for a 20 month period, the last term is and the series sum is

High schoolmathematics 5 points keith is the leading goal scorer for a team in an ice hockey league. last season, he scored 42 goals in 82 games. assuming he scores goals at a constant rate, what is the slope of the line that represents this relationship if the number of games is along the x-axis and the number of goals is along the y-axis?

Apositive number a or the same number a increased by 50% and then decreased by 50% of the result?