C1 : ( 2,45 + 7,55 ) x 2,75

= 10 x 2,75

= 27,5

C2 : ( 2,45 + 7,55 ) x 2,75
= 2,45 x 2,75 + 7,55 x 2,75
= 6,7375 + 20,7625
= 27,5

C1 : ( 25,5 - 17,15 ) x 100

= 8,35 x 100

= 835

C2 : ( 25,5 - 17,15 ) x 100
= 25,5 x 100 - 17,15 x 100
= 2550 - 1715
= 835

C1 : 5 x 67,35 x 20

= 336,75 x 20

= 6735

C2 : 5 x 67,35 x 20

= 5 x 20 x 67,35

= 100 x 67,35

= 6735

525 x 2019 - 2019 x 425 = 2019 x (525 - 425) = 2019 x 100 = 201900

\(525\times2019-2019\times425=2019\times\left(525-425\right)\)

                                                           \(=2019\times100\)

                                                           \(=201900\)

\(525.2019-2019.425\)

\(=\left(525-425\right).2019\)

\(=100.2019\)

\(=20190\)

525 x 2019 - 2019 x 425

= 2019 x ( 525 - 425 )

= 2019 x 100

= 201900

Hok tốt

   525 x 2019 - 2019 x 425

= 2019 x ( 525 - 425 )

= 2019 x 100

= 20190

525 . 2019 - 2019 . 425

= 2019 . ( 525 - 425)

= 2019 . 100

=201900 

\(1152-96\cdot y=\left(96\cdot y-96\cdot y\right)\cdot96\cdot y\)(dấu nhân viết là ".")

\(1152-96\cdot y=1\cdot96\cdot y\)

\(1152=96\cdot y+96\cdot y\)

\(1152=192\cdot y\)

\(y=\frac{1152}{192}\)

\(y=6\)

\(\dfrac{1}{4}:0,25-\dfrac{1}{8}:0,125+\dfrac{1}{2}:0,5-\dfrac{1}{16}:0,0625\\ =0,25:0,25-0,125:0,125+0,5:0,5-0,0625:0,0625\\ =1-1+1-1\\ =0+1-1\\ =1-1\\ =0\)

1/4:1/4-1/8:1/8+1/2:1/2-1/16:1/16

=1-1+1-1 

=0

= (30 x 2) + (20 x 5) + (25 x 4)

= 60 + 100 + 100

= 260

(30 : 0,5) + (20 : 0,2) + (25 : 0,25)

= (30 x 2) + (20 x 5) + (25 x 4)

= 60 + 100 + 100

= 260

`(30:0,5)+(20:0,2)+(25:0,25)`

`=(30xx2)+(20xx5)+(25xx4)`

`= 60  + 100 + 100`

`= 160 + 100`

`= 260`