Whats equivalent to -2x + 7

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

Complete the solution of the equation. find the value of y when x equals to 1 9x-5y=29

The area (a) of a circle with a radius of r is given by the formula and its diameter (d) is given by d=2r. arrange the equations in the correct sequence to rewrite the formula for diameter in terms of the area of the circle.