Somebody pls help me :,)

Solve the system of equations. y= 2x y= x^2 - 15

Which sentence uses an objective tone? we will plant the best garden of any school in the area. the new campus garden will surely be envied by other schools. a garden would provide numerous benefits to the students. you will probably agree that gardens have many benefits.

If cos(2x) = tan^2(y), show that cos(2y) = tan^2(x).