\(Bài1\\ a,=11600+25738=37338\\ b,=129620-75896=53724\\ c,=4000-6249=-2249\\ Bài2\\ a,=23.10=230\\ b,=2.5.34=10.34=340\\ c,=2.5.3.4=10.3.4=30.4=120\)
`1450 xx 8 + 25738=11600 + 25738 = 37338`
`32405 xx4 - 75896=129620- 75896 =53724`
`4000 - 56 241 : 9=4000-6249 = -2249`
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`23 xx 5 x 2 = 23xx(5xx2)=23xx10=230`
`2xx34xx5=(2xx5)xx34=10xx34=340`
`2xx3xx4xx5=(2xx5)xx3xx4=10xx3xx4=30xx4=120`
bài 1 ; tính
1450 x 8 + 25738
= (1450 x 8)+ 25738
= 11600+ 25738=37338.
32405 x 4 - 75896
=( 32405 x 4) - 75896
=129620-75896 =53724.
4000 - 56 241 : 9
= 4000 - (56 241 : 9)
=4000-6249
=-2249
bài 2 tính bằng cách thuận tiện
23 x 5 x 2 = ( 5x2) x23=23x10=230
2 x 34 x 5 = (2x5) x34=10x34=340
2x 3 x 4 x 5= (2x5)x3x4=10x12=120.