1. ac = bc vertical angles = 2. ∠1 = ∠2 substitution 3. ∠2 = ∠3 base ∠'s of isosceles triangle = 4. ∠1 = ∠3 given

Which statements about these triangles is true

Find the solution of this system of equation -7x+y=-20 9x-3y=36

60 musicians applied for a job at a music school. 14 of the musicians play both guitar and drums, 28 play drums, 18 play the guitar. what is the probability that the applicant who gets the job plays drums or guitar?