What is the expression for the calculation "subtract 10 divided into fifths from 20 divided into half"

What is the common difference in the following arithmetic sequence? 7,3,-1,-5

The table shows the balance of a money market account over time. write a function that represents the balance y(in dollars) after t years.

The marked price of an article is 25% above its selling price and the cost price is 30% less than its marked price . find the discount percent and gain percent. only a brainlest can solve it i will mark you brainlest