How can you tell if an equation (for example, x=16+3y (don’t solve this)) will be represented by a straight line when graphed on a coordinate plane? Is there an easy way to tell or how do you figure that out?

Find the slope of the line y =8/9x + 1.

Which graph represents the parent function of y=(x+2)(x-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