Ayuda por favor necesito explicacion de como se hace

Does the problem involve permutations or? combinations? do not solve. the matching section of an exam has 4 questions and 7 possible answers. in how many different ways can a student answer the 4 ? questions, if none of the answer choices can be? repeated?

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

Type the correct answer in each box. spell all words correctly. a sequence of transformations maps ∆abc onto ∆a″b″c″. the type of transformation that maps ∆abc onto ∆a′b′c′ is a . when ∆a′b′c′ is reflected across the line x = -2 to form ∆a″b″c″, vertex of ∆a″b″c″ will have the same coordinates as b′.