Question

The astronomical unit (AU) is the mean distance from the sun to the earth.

Answer 1

By definition, we have to
 1 AU = 1.5 * 10 ^ 8Km
 a comet is 2.3 AU from the earth, which means that we must transform this unit to kilometers.
 2.3 AU = (2.3) * (1.5 * 10 ^ 8) = 3.45 * 10 ^ 8km
 answer
 3.45 × 10,superscript,8,baseline, km

Answer 2

A. 3.45 x 10^8 km Since 1 AU is 1.5x10^8 and the comet is 2.3 AU away from Earth, the answer is a simple matter of multiplication. So: 1.5x10^8 km * 2.3 = 3.45x10^8 km Of the available options, option "A" matches exactly.