a)
[tex]28 \times (218 + 95) = \\ 28 \times 313 = 8764[/tex]
b)
[tex]56 \times 10 \times 39 = \\ 560 \times 39 = 21840[/tex]
c)
[tex]207 \times (207 \times 3) = \\ 207 \times 621 = 128547[/tex]