Why is it important to measure a earthquake

Which number shows the location of the united kingdom of great britain? 7 5 2 4

One of the brightest comets of the 20th century was comet hyakutake, which passed close to the sun in early 1996. the orbital period of this comet is estimated to be about 30,000 years. find the semi-major axis of this comet’s orbit. compare it to the average sun-pluto distance and to the distance to alpha centauri, the nearest star to the sun, which is 4.3 light-years distant.

Find the coordinates of a if b(-9,-10) is the midpoint of ac and c has the coordinates of (-1,9)