I really need help can someone please understand

"you know, playing tennis is healthier than watching a tennis match on television," katya remarked to her couch potato brother. in this sentence, healthier is a/an a. superlative. b. comparative. c. positive form. d. adverb.

Acube has a volume of 800 cubic inches. whatis the length of an edge of the cube, in inches? a. 23/100b. 43/50c. 83/100d. 1003/2e. 1003/8

Solve the system of equations. x=-2y+1 and x+2y=9. show work