\(43\cdot59+57\cdot59-43\cdot21-57\cdot21\)
\(=59\left(43+57\right)-21\left(43+57\right)\)
\(=3800\)
=59.(43+57)-21.(43+57)
=59.100-21.100
=100.(59-21)
=100.38
=3800
43 . 59 + 57 . 59 - 43 . 21 - 57 . 21
= 2537 + 3363 - 903 - 1197
= -826 - 294
= -1120
43⋅59+57⋅59−43⋅21−57⋅2143⋅59+57⋅59−43⋅21−57⋅21
=59(43+57)−21(43+57)=59(43+57)−21(43+57)
=3800