algebra help

Question

suppose a spacecraft recently started on a journey inside the solar system. the trip is 4.5 x 10⁹  

miles long and will take 8 1/2 years. How many miles will the spacecraft travel per year?

Answer 1

4.9 x 10^9 divided by 8.5 = 4.9/8.5 x 10^9

= 0.58 x 10^9 = 5.8 x 10^8 miles per year

= 5.8/365(24) x 10^8 = 7.7 x 10^4 mph

speed of light = 6.7 x 10^8 mph