Final answer:
To subtract 2.5 x 10⁸ from 4.7 x 10⁸ with due regard to significant figures, subtract the numbers and keep the same number of significant figures as the number with the fewest significant figures. The result is 2.2 x 10⁸.
Step-by-step explanation:
To subtract 2.5 x 10⁸ from 4.7 x 10⁸ with due regard to significant figures, we need to make sure that our final answer has the same number of significant figures as the number with the fewest significant figures.
Both numbers have the same number of significant figures, which is two. Therefore, we can subtract them without worrying about significant figures. The calculation is as follows: (4.7 - 2.5) x 10⁸ = 2.2 x 10⁸.