Question

430x69＋690x57，111x28＋999x8能不能用简便方法计算吗

Answer 1

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Answer 2

430x69＋690x57，
=430×69+69×10×57
=（430+570）×69
=1000×69
=69000

111x28＋999×8
=111×28+111×9×8
=111×（28+72）
=111×100
=11100

Answer 3

430x69＋690x57
=43x690＋690x57
=(43+57)×690
=100×690
=69000
111x28＋999x8
=111x28＋111×9x8
=111x（28＋9x8）
=111×100
=11100

Answer 4

430×69+690×57
=43×690+690×57
=(43+57)×690
=100×690
=69000
111×28+999×8
=111×28+111×9×8
=111×28+111×72
=111×(28+72)
=111×100=11100

Answer 5

430x69＋690x57
=690x(43+57)
=690x100
=69000
111x28＋999x8
=111x(28+9x8)
=111x100
=11100