Please help me I've been stuck on hours

For the sequence [tex]a_{n} = 2n/(n+1)[/tex], what is the value of [tex]a_{10}[/tex]

Hich polynomial correctly combines the like terms and expresses the given polynomial in standard form? 8mn5 – 2m6 + 5m2n4 – m3n3 + n6 – 4m6 + 9m2n4 – mn5 – 4m3n3

Light travels at 186,000 miles per second. light takes about 1 1? 3 seconds to travel from the earth to the moon. calculate the distance between the earth and the moon based on the speed of light.