I'm pretty sure the answer is c
2(2x-1) + 2(3x)=4x-2+6x = 10x - 2 & not <span>=10x-1</span>
All you do is add them all together...
20 + 11.4 + 11.4 + 4.5 + 4.5 + 0.45 + 0.45 + 0.45 + 0.45 = 53.6Kg
(note that 0.45 is 450g in Kg, When adding things such as weight or length you want to make sure that they are all in the same unit)

where r is the radius of a circle.
D. I would best guess, hey have a nice thanksgiving week. Hope they gave you a whole week of school out like mine did :) if you go to school