Answer: 799800000
Step-by-step explanation: For 8 x 10^8, do 10 x 10 x 10 10 x 10 x 10 10 x 10 to get 100,000,000 and x 8 is 800,000,000
For 2 x 10^5 do 10^5 ( 10 x 10 x 10 x 10 x 10) which is 100,000 and then x 2 is 200,000
Then subtract.
800,000,000 - 200,000 is 799800000