Answer:
1, D
2,D
3,B
hopefully this helps you! I'm not too sure but sure enough :)
steps:
1. The answer is none of the above because if you multiply for example 51 x 10 8 it'd be 51 x 80 which is not the answer because 51 x 80 is 4080 which is not 510 000 000.
2. The answer is none of the above because if you divide 0.0763/1.85+4.7x8 it would equal 37.6 which unfortunately isn't an answer above.
3. Finally the answer for this one is B because if you have 8/9 - 5/7 it would equal 11/63 I subtracted 8 and 9 and made sure the bottom numbers were the same, and I simplified.
hopefully THIS helps you?