bantu jawaaaabbbbbb :(

1) 3x + 3    = - 2x + 18                           x + 1 = 3 + 1
     3x + 2x = 18 - 3                                         = 4         (B)
             5x = 15
               x = 3

2)  f(x) = 4x - 3   dan   f(d) = 17   maka
     f(d) = 4d - 3
     17 = 4d - 3
     4d = 17 + 3
       d = 20/4
       d = 5

3)  x - 3y = 1                                 jika y = 1 → x - 3y   = 1
     x - 2y = 2                                                     x - 3(1) = 1
    ---------------- -                                                      x    = 1 + 3
         -y  = -1                                                           x    = 4
          y  = 1

     sehingga 2x - 5y = 2(4) - 5(1)
                                = 3     (C)