Hey. I have a 45 minute time limit and I haven’t got a clue what I’m doing. Help? <3

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

Two corresponding sides of two similar triangles are 3cm and 5cm. the area of the first triangle is 12cm^2. what is the area of the second triangle?

Me! i will mark brainliest! i don't get polynomials and all that other stuff. so this question is really hard. multiply and simplify.(x - 4) (x^2 – 5x – 6)show your