Dr. sox paid $1580 for a new computer system. she also paid a 6.5% sales tax. how much was the tax?

Express the following as a function of a single angle, cos(60) cos(-20) - sin(60) sin(-20)

If a 36 inch yardstick casts a 21 foot shadow, how tall is a building whose shadow is 168 feet? what is the scale factor

Sue's average score for three bowling games was 162. in the second game, sue scored 10 less than in the first game. in the third game, she scored 13 less than in the second game. what was her score in the first game?