\(a,=69,78\times\left(\dfrac{3}{4}+\dfrac{1}{4}+99\right)\\ =69,78\times\left(\dfrac{4}{4}+99\right)\\ =69,78\times\left(1+99\right)=69,78\times100=6978\\ b,34,1\times8+34,1\times0,5\\ =34,1\times\left(8+0,5\right)\\ =34,1\times8,5\\ =289,85\)

a: =69,78(3/4+1/4+99)

=69,78*100

=6978

b: =34,1(8+0,5)=34,1*8,5=289,85

a.\(69,78\times\dfrac{3}{4}+69,78\times\dfrac{1}{4}+69,78\times99=69,78\times\left(\dfrac{3}{4}+\dfrac{1}{4}+99\right)=69,78\times100=6978\)

b. \(34,1\times8+34,1\times0,5=34,1\times\left(8+0,5\right)=34,1\times8,5=289,85\)

ko ai bt à

Lời giải:
$=27\times 2+12,44\times 4+17,56\times 4+23\times 2$

$=2\times (27+23)+4\times (12,44+17,56)$

$=2\times 50+4\times 30$

$=100+120=220$

a) \(6,15:0,5+6,15:0,2+3x6,15\)

\(=6,15x\left(1:0,5+1:0,2+3\right)=6,15x\left(2+5+3\right)=6,15x10=61,5\)

b) \(0,215x74,24+25,76x0,215+18,5\)

\(=0,215x\left(74,24+25,76\right)+18,5=0,215x100+18,5=21,5+18,5=40\)

`@` `\text {Ans}`

`\downarrow`

`4,`

`a)`

\( 6,15 \div 0,5 + 6,15 \div 0,2 + 3 \times 6,15 \)

`= 6,15 \times 2 + 6,15 \times 5 + 3 \times 6,15`

`= 6,15 \times (2 + 5 + 3)`

`= 6,15 \times 10`

`= 61,5`

`b)`

`0,215 \times 74,24 + 25,76  \times 0,215 + 18,5 `

`= 0,215 \times (74,24 + 25,76) + 18,5`

`= 0,215 \times 100 + 18,5`

`= 21,5 + 18,5`

`=40`

\(12,5:0,5+12,5:0,25+12,5:0,125-12,5\times4\)

\(=12,5\times2+12,5\times4+12,5\times8-12,5\times4\)

\(=12,5\times\left(2+4+8-4\right)\)

\(=12,5\times10\)

\(=125\)

_HT_

12,5 : 0,5 + 12,5 : 0,25 + 12,5 : 0,125 – 12,5 x 4

\(=12,5\left(2+4+8-4\right)\)

\(=12,5.10=125\)

125 nhé bạn

= 12,5 x 2 + 12,5 x 4 + 12,5 x 8 - 12,5 x 4

= 12,5 x (2+4+8-4)

= 12,5 x     10

=     125

Ta có:

\(12,5:0,5+12,5:0,25+12,5:0,125-12,5×4\)

\(=12,5:\left(0,5+0,25+0,125\right)-12,5×4\)

\(=12,5×10\)

\(=125\)