Need answer asap.

a polyhedron has 9 faces and 9 vertices. how many edges does it have? what is the name of this solid figure?

Which values for a and b will create infinitely many solutions for this system of equations? ax-y=8 2x+y=b

"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.

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.