13,25 :0,5 +13,25 :0,25 +13,25 :0,125

= 13,25 x 2 +13,25 x 4 +13,25 x 8

= 13,25 x ( 2 + 4 + 8 )

=13,25 x 14 = 185,5

= 13,25  nhân 2 + 13,25 nhân 4 = 13 , 25 nhân 8

=13,25 nhân [ 2 + 4 + 8]

=13,25 nhân 14

=185,5

thanks 2 bạn

Đề bài:tính bằng cách thuật tiện nhất.(Biết A+B+C=20,19)

45,54.B+67,76.A+89,98.C+32,24.A+10,02.C+54.46.B

= B.(45,54 + 54,46) + A.(67,76 + 32,24) + C.(89,98 + 10,02)

= B.100 + A.100 + C.100

= 100.(A + B + C)

= 100.20,19

= 2019

có đúng ko vậy các bạn ??????????????

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a) 98+3+97+2
= (98+2)+(97+3)
= 100 + 100
= 200

 56+399+1+4
= (56+4)+(399+1)
= 60 + 400
= 460

b)364+136+219+181
= (364+136)+(219+181)
= 500 + 400
= 900

 178+277+123+422
= (178+422)+(277+123)
= 600 + 400
= 1000
 

a) 98+3+97+2
= (98+2)+(97+3)
= 100 + 100
= 200

 56+399+1+4
= (56+4)+(399+1)
= 60 + 400
= 460

b)364+136+219+181
= (364+136)+(219+181)
= 500 + 400
= 900

 178+277+123+422
= (178+422)+(277+123)
= 600 + 400
= 1000

\(45,54B+67,76A+89,98C+32,24A+10,02C+54,46B\)

\(=100A+100B+100C\)

\(=100\left(A+B+C\right)\)

\(=100.20,19\)

\(=2019\)

\(12,1+12,1\cdot101+99\cdot12,1-101\cdot12,1\)

\(=12,1\cdot\left(1+101+99-101\right)\)

\(=12,1\cdot\left(1+99\right)\)

\(=12,1\cdot100\)

\(=1210\)

`12,1 + 12,1 x 101 + 99 x 12,1 - 101 x 12,1`

`= 1 x 12,1 + 12,1 x 101 + 99 x 12,1 - 101 x 12,1`

`= 12,1 x (1 + 101 + 99 - 101)`

`= 12,1 x 100`

`= 1 210`

\(=0,18\left(0,2\cdot950+1\right)+3\left(242\cdot2+3\right)=1495,38\)

\(=0,18\left(0,2\cdot950+1\right)+3\left(242\cdot2+3\right)=1495,38\)

Ta có: 0,15x400

=0,15 x 4 x 100= 0,6 x 100=60

0,15 x 400 = 0,15 x 100 x 4 

                  = 15 x 4

                   = 60