10 to the nth power = 5, what is n equal to

10 to the nth power = 5, what is n equal to

10^n=5
So n = lg5

The problem of light year conversion: stars are far away, the distance between a light running 30000km / s and stars is calculated. 1) how many km is a light year
2) If the vision, that is, the center of vision, is 2, how many km and how many light years can we calculate the distance
The second question a light Eris 13 hours to reach the earth to calculate the distance Eris to the earth

The distance light travels in a year is called a light year. The speed of light is 300000 kilometers per second, so a light year is 9460 billion kilometers
30000km / s * 13 * 3600s = 14.04 billion km

How many laps can you run around the earth in one light year? What's the simplest formula/

Light years are not time. Light can circle the earth seven times a second

The second power of x plus 3x minus 1 minus - --- equal to the second power of 2x minus x minus 7

x^2+3x-1-2x^2+x+7
=-x^2+4x+6