Your local gas stations are having a price war. during the past 7 days they have lowered the price of regular gas by $.02 each day. define a variable. then write and solve an equation to find the total change in gas price. show your work. need answer asap

Use sigma notation to represent the following series for 9 terms.

Three friends are comparing the prices of various packages of golf balls at a sporting goods store. hector finds a package of 6 golf balls that costs $4.50.

The students at jefferson middle school are raising money for a charity by selling t-shirts and hats. the number of t-shirts sold was 3 times the number of hats. the profit was $5 for each t-shirt sold and $2.50 for each hat sold. the students raised $840 for the charity. they used the system below to analyze their success and found the solution to be (144, 48). 5x+2.50y=840 x=3y how much did they earn from t-shirt sales?