Can you help me with this ASAP I will give 15 points. please do it with a response. Thank you so much

Sam claims that cos x =sin y if x and y are congruent angels. is sam correct ?

Gabrielle's age is two times mikhail's age. the sum of their ages is 84. what is mikhail's age?

You just purchased two coins at a price of $670 each. because one of the coins is more collectible, you believe that its value will increase at a rate of 7.1 percent per year, while you believe the second coin will only increase at 6.5 percent per year. if you are correct, how much more will the first coin be worth in 15 years?