Solve the following pairs of simultaneous equations.
a) 2x - 2y = -4
5x + 4y = 17
b) 2x - 3y = 6
4x - 5y = 9
c) x / 3 + y / 2 = 3 / 2
x / 2 + y / 5 = -1 / 2

Brian, chris, and damien took a math test that had 20 questions. the number of questions brian got right is 14 more than the number of questions chris got right. damien correctly answered 2 less than the number of questions chris answered correctly. if brian and damien have the same score, which statement is true?

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?

Which expression represents the total perimeter of her sandwich, and if x = 1.2, what is the approximate length of the crust?