37 x 25 + 37 x 35 + 37x 39 +  37

= 37x ( 25+ 35+ 39 + 1)

= 37 x 100

= 3700

a: =428(36+64)=42800

b: =512(47-37)=5120

c: =72x100=7200

\(428×(36+64)\)

\(=428×100\)

\(=42800\)

\(512×(47-37)\)

\(=512×10\)

\(=5120\)

\(72×(4×25)\)

\(=72×100\)

\(=7200\)

\(\left(\dfrac{4+5}{9}\right)\text{×}\dfrac{3}{7}\)

\(=1\text{×}\dfrac{3}{7}\)

\(=\dfrac{3}{7}\)

251/431 x 29/ 37 + 251/431 x 8/ 37

= 251/431 x (29/ 37 + 8 /37)

= 251/ 431 x 37/37

= 251/ 431 x 1 = 251/431

2364 x 37 + 2364 x 63  = 2364 × (37 + 63)

= 2364 × 100

= 236400

135 x 37 + 135 +  62 x 135

= 135 x 37 + 135 x 1 +  62 x 135

= 135 x ( 37 + 1 + 62)

 = 135 x 100

= 13500

19.9+9.(37+43)+9

=19.9+9.80+9

=9.(19+80+1)

=9.100

=900

`#Ya`

`= 19 × 9 + 9 × 80 + 9 × 1`

`= 9 × ( 19 + 80 + 1 )`

`= 9 × 100= 900`

\(a.=34,56\times\left(6+3+1\right)\)

\(=34,56\times10\)

\(=345,6\)

\(b.=75,18\times\left(34+37+28+1\right)\)

\(=75,18\times100\)

\(=7518\)

Nè tớ thấy đề bài bạn hơi sai sai

Tớ nghĩ:'' a,34,56x6+34,56x3+34,56'' thì đúng hơn

a) 218 x 37 + 218 x 62 + 218 = 218 x (37 + 62 + 1) = 218 x 100 = 21800

` 10000 – 47 xx 72 – 47 xx 28 `
`=10000-47xx(72+28)`
`=10000-47xx100`
`=100xx100-47xx100`
`=100xx(100-47)`
`=100xx53`
`=5300`

`10 000 - 47 xx 72 - 47xx28`

`=10 000 - 47 xx(72+28)`

`=10 000 - 47xx100`

`=10 000 - 4700`

`=5300`

Tính bằng cách thuận tiện :

 37 x 68 + 123 x 74

= 37 x 68 + 123 x 2 x 37

= 37 x 68 + 246 x 37

= 37 x ( 246 + 68 )

= 37 x 314

= 11618

37 x 68 + 123 x 74 

= 37 x 68 + 123 x 2 x 37 

= 37 x 68 + 37 x 246 

= 37 x ( 68 + 246 ) 

= 37 x 314 

= 11618