Question 98805
       Find values for m and b in the following system so that the solution to the system is (-3, 4). 
5x+7y = b
mx+y = 22

  substituting the values of x and y as -3 and 4 in the eq'ns we get 

             5(-3)+7(4) = b   i.e -15+28 = b  or b = 13

             m(-3)+(4) = 22  i.e  -3m = 22-4
                                   -3m = 18

                                     m = 18/-3 = -6

           the values of m = -6  and b = 13