Which choice (s) when rounded to the nearest hundred thousand will result in 600,000?

To solve this start with the 146,790 place so in this example 1. Look to the Ten thousand's place and you see a 4 If it's 4 or less let it rest. If it was 5 above climb the vine. :3 
So in this example it would be 100,000 because 4 wouldn't make the 1 turn to 2.
Hope that helps. :3

Basic algebra equation. first set up your equation: divide out 9.and now you are left with 2x + 4 = 8.