Answer:
1 significant figure: 50,000 2 significant figures: 52,000 3 significant figures: 51,800
Explanation:
FIrst, a significant figure is basically a non-zero digit (at least in your case). Basically, the 1 significant figure in your case would be to the nearest 10 thousand, which would be 50,000. Now, for 2 significant figures. This would be the nearest thousand, 52,000. Finally, 3 significant figures is to the nearest hundred, aka 51,800. Note: If you find a problem like this again 0 in between two digits that aren't 0 is a significant digit, aka the 0 in 51809. Hope this helped!