What is the solution to the system of equations?

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

What are the coordinates of the point is 1/4 of the way from a (-6, -3) to b (6, 1)? a. (-3, -2) b. (0, -2) c. (-1, 0) d. (3, 2)

Is the number 128.439 a rational number