Which of the following is not a solution of the equation 2x+y=7.
(1,3) is not a solution of the equation 2x + 5y = 18
Let A = {1,2,3}, B = {1,3,5}. A relation R:A → B is
defined by R = {(1,3),(1,5),(2,1)}. Then R−1 is defined by