Solve each system of equations

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

What are the solutions to the following equation? |m| = 8.5 the value of m is equal to 8.5 and because each distance from zero is 8.5.

Given the system of equations presented here: 2x + 4y = 14 4x + y = 20 which of the following actions creates an equivalent system such that, when combined with the other equation, one of the variables is eliminated? multiply the second equation by â’4 to get â’16x â’ 4y = â’80 multiply the second equation by â’1 to get â’4x â’ y = â’20 multiply the first equation by 2 to get 4x + 8y = 28 multiply the first equation by â’1 to get â’2x â’ 4y = â’14