Final answer:
Subtracting 4.66×10−5 and 7.34×10−7 is done by equating the exponents and performing the subtraction, giving a result of 4.5866×10−5, rounded to 4.59×10−5. However, the closest answer choice without rounding is (a) 4.66×10−5.
Step-by-step explanation:
To subtract the numbers 4.66×10−5 and 7.34×10−7, we need to express them with the same exponent. We can rewrite 7.34×10−7 as 0.0734×10−5 so that both terms have the exponent −5. Now, subtraction is straightforward:
4.66×10−5 – 0.0734×10−5 equals 4.5866×10−5.
Now we express the result in proper scientific notation. Since the number 4.5866 is already between 1 and 10, we can write the final answer as 4.5866×10−5, which rounds to 4.59×10−5 when rounded to three significant figures.
None of the given options (a) 4.66×10−5, (b) 4.66×10−6, (c) 4.66×10−4, or (d) 4.66×10−7 exactly match the correct answer, but option (a) is the closest without rounding.