H(2-6)=x² + 8x

I have to use this for an answer for functions idk what it is

Angel entered a triathlon (a three-part race). he swam 1 mile, rode his bike 30 miles, and ran 10 miles. how far did he go altogether? a. 11 miles b. 123 miles c. 41 miles d. 40 miles

Someone answer this check out the image!

Ineed with number 6 , explain how to get 1978