Answer:
2(u+3v)
2 times u is 2u and then 2 times 3v is 6v.
2u+6v
They are more atoms in a body, only 75,000,000,000,000,000,000 grains of sand
and
7,000,000,000,000,000,000,000,000,000
atoms in a body, at the end , the number of atoms seem longer and larger.