Be sure to simplify your answer. any help is appreciated !!

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

Beth divided 9 ounces of her granola recipe into 4 equal-sized amounts. she placed the amounts into individual bowls. the fraction 9/4 represents the number of ounces of granola in each bowl. which other number represents the amount of granola beth has in each bowl? (a) 1 1/4 (b) 2 1/4 (c) 1 3/4 (d) 3 3/4 i need !

Joe has a rectangular chicken coop. the length of the coop is 4 feet less than twice the width. the area of the chicken coop is 510 square feet. what is the length of the chicken coup?