Guys I need help Problem solving Question: If 5 men can reap a field in 9 days, how many days 15 men take to reap the field

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

9/10 divide by -3/15 as a mixed number

Which of the following values are in the range of the function graphed below? check all that apply ! - will give the answer "brainliest! "