tolong ya nomor 9 10 14

9. f(x) = ax+b
    f(2) = 2a + b = -2
    f(3) = 3a + b = 13
              -a          = -15
                a         = 15
         2(15) + b = -2
          30 +b = -2
                  b = -2-30 = -32
f(4) = 15(4) -32
         = 60-32=28