What is 7(3x+5y) simplified

The vertices of a triangle are a(7,5), b(4,2), c(9,2). what is m

What is the equation of a line passing through the point (6,1) and parallel to the line whose equation 3x=2y+4

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