Show that the Pythagorean identity sin^2 θ + cos^2 θ = 1 is true for the given angle. θ = 5π/3

Ijust need to see how to do this. so you don’t have to answer all of them just a step by step explanation of one.

Awasher and a dryer cost $701 combined. the washer costs $51 more than the dryer. what is the cost of the dryer?

Pls never taught i’m really confused and i rlly need