The single equivalent discount rate of 9/5/4 is .17008. true or false?

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

Avery’s piggy bank has 300 nickels, 450 pennies, and 150 dimes. she randomly picks three coins. each time she picks a coin, she makes a note of it and puts it back into the piggy bank before picking the next coin.

Simplify using positive exponents only.