Help please just this question for a test

Florence price's brownies and more sells all types of cookies and pastries. on tuesdays, they markdown all brownies 75% to a sale of $1.50 a dozen. find the selling price and the markdown of a dozen brownies.

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

Indicate the formula for the following conditions: p^c(n,r)=