Yes;k=-3 and y=-3x is the answer because 2 x -3 = -6 -3 x -3 = -9 and etc..
        
             
        
        
        
First you grapgh 0,-3 then you follow the slope of going 4 up 5 to the right and contine up also on e-where it is 0,-3 you go down 4 and 5 to the left and contine that to make a straught line.
        
             
        
        
        
We have to find the volume of tank. The tank is in cuboid or rectangular prism shape
Volume = depth*height*width
 = 12*24*18
 = 5184 cubic inches