To determine the number of miles Bob flew last year, follow these steps:
1. Understand the question: We are given that two years ago, Bob flew [tex]\( 6 \times 10^5 \)[/tex] miles. This distance is 15 times the number of miles he flew last year. We need to find out how many miles he flew last year.
2. Assign values to known quantities:
- Miles flown two years ago: [tex]\( 6 \times 10^5 \)[/tex] miles.
- This amount is 15 times the miles flown last year.
3. Set up the equation:
Let [tex]\( x \)[/tex] be the number of miles Bob flew last year.
According to the problem, two years ago Bob flew 15 times the miles he flew last year:
[tex]\[
6 \times 10^5 = 15x
\][/tex]
4. Solve for [tex]\( x \)[/tex]:
Divide both sides of the equation by 15 to isolate [tex]\( x \)[/tex]:
[tex]\[
x = \frac{6 \times 10^5}{15}
\][/tex]
5. Simplify the right side of the equation:
[tex]\[
x = \frac{6 \times 10^5}{15} = \frac{6 \times 10^5}{15} = 4 \times 10^4
\][/tex]
6. Determine the correct option:
From our calculations, [tex]\( x = 4 \times 10^4 \)[/tex] miles.
Hence, Bob flew [tex]\( 4 \times 10^4 \)[/tex] miles last year. Therefore, the correct answer is:
(a) [tex]\( 4 \times 10^4 \)[/tex] miles
