Question

Stronomers measure large distances in light-years. One light-year is the distance that light can travel in one year, or approximately 5,880,000,000,000 miles. Suppose a star is 14.4 light-years from Earth. In scientific notation, how many miles away is it
5.88 x 1013 miles 1.44 x 1012 miles 5.88 x 1012 miles 8.4672 x 1013 miles

Answer 1

This is one of those problems where you don't actually have to know anything. The only answer that is any combination of the two given numbers is the last one:
.. 8.4672*10¹³ miles

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That result is the product of 5.88*10¹² and 14.4.