FPB dri 28,84 dan 96 adalah.... tolong kasih caranya yh..plzz

28            84              96                 
∧              ∧                ∧
2 14         2 42           2  48
     ∧             ∧                ∧
    2 7          2  21            2 24
                        ∧                 ∧
                       3  7               2 12
                                                 ∧
                                                 2 6
                                                     ∧
                                                     2 3

28=2×2×7
84=2×2×3×7
96=2×2×2×2×2×3
FPB=2×2=4