2x + y = 5
8x – y = 45
what is the ordered pair

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

The volume of the a sphere whoes diameter is 18 cm is cubic cm . if it's diameter were reduced by half, it's volume would be of its original volume

Points j and k plotted on the coordinate grid are two vertices of rectangle jklm rectangle jklm has an area of 7 square units point j is located at 2,1 and point k is located at -5,1 each vertex of the rectangle is located at a point that has integer coordinates. what is the perimeter of rectangle jklm? (need answer asap)