In ΔABC what is the value of x?

What are the solutions of the system? solve by graphing. y = -x^2 -6x - 7 y = 2

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters

Describe the symmetry of the figure. identify lines of symmetry, if any. find the angle and the order of any rotational symmetry.