Question

用简便方法计算，50X209X4？39Ⅹ49十61X49？125X4X8X25？(40十6)X25

Answer 1

125x26x4X8X5X20X25
=（125x8）x（25x4）x（20x5）x26
=1000x100x100x26
=260000000

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Answer 2

50 x 209 x 4 = (50 x 200) x 4 + (50 x 9) x 4 = 40,000 + 1,800 = 41,800
39 x 49 x 61 x 49 = (39 x 49) x (49 x 61) = 1,911 x 2,989 = 5,715,779
125 x 4 x 8 x 25 = 125 x (4 x 8) x 25 = 125 x 32 x 25 = 100,000
(40 x 6) x 25 = 240 x 25 = 6,000

Answer 3

50*209*4
=50*4*209
=200*209
=41800

39*49+61*49
=（39+61）*49
=100*49
=4900

125*4*8*25
=125*8*（4*25）
=1000*100
=100000

（40+6）*25
=40*25+6*25
=1000+150
=1150