My song lol. Help me plz

Simplify (4x^2 - 8xy + 2y^2) - (9x^2 - 4xy - 7y^2) a. -5x^2 + 4xy + 9y^2 b. -5x^2 - 4xy + 9y^2 c. -5x^2 + 12xy + 4y^2 d. -5x^2 - 4xy - 5y^2

60 musicians applied for a job at a music school. 14 of the musicians play both guitar and drums. what is the probability that the applicant who gets the job plays drums or guitar?

I’m really confused and need your assist me with this question i’ve never been taught