66X21+19X21+85X19怎么简便计算?还有(125+75)X28、36X111+888X8、99X99+199怎么简便计算?

来源:学生作业帮助网 编辑:作业帮 时间:2024/07/17 20:13:52
66X21+19X21+85X19怎么简便计算?还有(125+75)X28、36X111+888X8、99X99+199怎么简便计算?
xő1n0S) ~تC=@ ,]ݡrH8J$Wȳ1$ :`o p@U X|v*?s=U<~mں.hX'h3)J5/o]ƿy9"bO##ؒԠ }5Mz c:~ϟ_pL|}gio$e}ѕu)gA [o2PFEOc1&aRҹWK[]13

66X21+19X21+85X19怎么简便计算?还有(125+75)X28、36X111+888X8、99X99+199怎么简便计算?
66X21+19X21+85X19怎么简便计算?
还有(125+75)X28、36X111+888X8、99X99+199怎么简便计算?

66X21+19X21+85X19怎么简便计算?还有(125+75)X28、36X111+888X8、99X99+199怎么简便计算?
66X21+19X21+85X19
=21(66+19)+85X19
=21X85+85X19
=85(21+19)
=85X40
=3600

66X21+19X21+85X19
=(66+19)×21+85×19
=85×21+85×19
=85×(21+19)
=85×40
=3400
(125+75)X28
=200×28
=5600
36X111+888X8
=36×111+111×64
=(36+64)×111
=100×111
=11100
99X99+199
=99×99+2×99+1
=(99+1)²
=100²
=10000