I need awnser asap im giving brainlist in this one

8/1 x 8

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

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.

What are the solutions for the following system? -2x^2+y=-5 y=-3x^2+5