Okay so your problem is, the question is (6x10^3)-(2x10^9). So in the () do 10^3 first okay? You get 1,000. so 1,000x6 is?6,000. next one is 2x10^9.10^9 is 1,000,000,000. Then you got a 2 in there and so on.
Now 2,000,000,000-9,000?199999400. Then scietific notation.
1.999994x10^8
