35 x 3/4 + 45,5 x 75/100 + 20,5 x 75% - 0,75

= 35 x 0,75 + 45,5 x 0,75 + 20,5 x 0,75 - 0,75 x 1

= ( 35 + 45,5 + 20,5 - 1 ) x 0,75

= 100 x 0,75

= 75

35 x 3/4 +45,5 x 75/100 + 20,5 x75% - 0,75 

= 35. 0,75 + 45,5 . 0,75+ 20,5 . 0,75 - 0,75.1

= 0,75( 35+45,5 + 20,5 -1)

= 0,75.100

= 75

=3/4.0,25+3/4.1,25-3/4.0,5

=3/4.(0,25+1,25-0,5)

=3/4.10

=15/2

`3/4.0,25+3/4.1,25-3/4.0,5`

`=3/4.(0,25+1,25-0,5)`

`=3/4xx10=15/2`

=3/4x(0,25+1,25-0,5)=3/4x10=15/2

( 3092 x 0,75 - 408 x 3/4 ) : 6/4

= ( 3092 x 0,75 - 408 x 0.75 ) x 4/6

= 0,75 x (3092- 408) x 4/6

= 3/4 x 2684 x 4/6

= 12/24 x 2684

= 0,5 x 2684

= 1342

(3092 x 0,75 - 408 x 3 phần 4) : 6 phần 4

=(2319        -      306       )     : 6 phần 4

=            2013                :       6 phần 4

=              1342

a) \(0,75x99+\dfrac{3}{4}=\dfrac{3}{4}x99+\dfrac{3}{4}=\dfrac{3}{4}x\left(99+1\right)=\dfrac{3}{4}x100=75\)

b) \(3,05x8+9,15-3,05=3,05x8+3x3,05-3,05=3,05x\left(8+3-1\right)=3,05x10=30,5\)

\(\frac{30}{11}\times\frac{66}{25}\times\frac{75}{210}\)

\(=\frac{30\times6\times11\times3\times25}{11\times25\times30\times7}\)

\(=\frac{18}{7}\)

\(\left(\frac{8}{11}+\frac{3}{12}\right)+\frac{3}{11}\)

\(=\frac{8}{11}+\frac{3}{12}+\frac{3}{11}\)

\(=\left(\frac{8}{11}+\frac{3}{11}\right)+\frac{3}{12}\)

\(=1+\frac{3}{12}\)

\(=\frac{5}{4}\)

Matcha

\(\frac{30}{11}\times\frac{66}{25}\times\frac{75}{210}\)

\(=\frac{30\times66\times75}{11\times25\times210}\)

\(=\frac{1\times6\times3}{1\times1\times7}\)

\(=\frac{18}{7}\)

\(\left(\frac{8}{11}+\frac{3}{12}\right)+\frac{3}{11}\)

\(=\frac{8}{11}+\frac{3}{12}+\frac{3}{11}\)

\(=1+\frac{3}{12}\)

\(=1+\frac{1}{4}\)

\(=\frac{5}{4}\)

30/11 x 66/25 x75/210

= \(\frac{30.66.75}{11.25.210}\)

=\(\frac{1.6.3}{1.1.7}\)

\(=\frac{18}{7}\)

(8/11+3/12)+3/11

\(=\frac{8}{11}\)\(+\frac{3}{12}\)\(+\frac{3}{11}\)

= ( \(\frac{8}{11}\)+ \(\frac{3}{11}\)) + \(\frac{3}{12}\)

= \(1+\frac{1}{12}\)

=\(\frac{5}{4}\)

`@` `\text {Ans}`

`\downarrow`

`a)`

`20 \times 6 \times 5 \times 7`

`= (6 \times 7) \times (20 \times 5)`

`= 42 \times 100`

`= 4200`

`b)`

`125 \times 789 \times 8`

`= (125 \times 8) \times 789`

`= 1000 \times 789`

`= 789000`

`c)`

`2 \times 3 \times 4 \times 8 \times 50 \times 25 \times 125`

`= (2 \times 50) \times 3 \times (4 \times 25) \times (8 \times 125)`

`= 100 \times 3 \times 100 \times 1000`

`= 300000000`

a) 20 x 6 x 5 x 7

= ( 20 x 5 ) x ( 6 x 7 )

= 100 x 42

= 4200