What is the value of x

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

Student price tickets to a movie are $1 and non student tickets are $2 . 350 tickets are sold and the total amount made is $450. there were 250 student tickets sold . true or false .

Explain why the factor 1.5 is broke. into two numbers in the model.