Please help? :) =)

Carrie and krystal are taking a road trip from greenville each person has her own map carry in north valley or each person has her own map in the scales on the maps are different and carries map read about in northville are 4.5inches apart the scale on a map is 1 inch equals 20 miles how far is greenville from north valley

What is the axis of symmetry of the function f(x)=-(x+ 9)(x-21)

Simplify. 4+3/7x-2-2/7x a. 2-5/7x b. 6-1/7x c. 2+1/7x d. 6+5/7x