B. Divide the next number by four and just reverse the sign.
Answer:
Hence, 3,40,000 can be expressed as 
Step-by-step explanation:
Step 1 of 1
Consider 3,40,000
3.4
So, 3.4 lies between 1 & 10
Now, Decimal has moved 5 places to left.

So, 3,40,000=
- abc + 7abc - 3bc - 8abc
= 6abc - 3bc - 8bc
= -2abs - 3bc
Therefore
- 2abc - 3bc.
:)