a) = 8 . 15 - [115- 7² ]

     = 8 . 15 - [115- 49 ]

     = 120    - 56

      = 64

b) = 100 : {250 : [450 - (2.125 - 8.25)]}

    = 100 : {250 : [450 - (250 - 200 )]}

     = 100 : {250 : [450 - 50]}

     = 100 : {250 :400}

     = 100 : 0,265

      = 0,00265

     = 

     

\(a,2^3.15-\left[115-\left(12-5\right)^2\right]\)

\(=8.15-\left[115-\left(12-5\right)^2\right]\)

\(=120-\left[115-7^2\right]\)

\(=120-\left[115-49\right]\)

\(=120-66\)

\(=54\)

\(b,100:\left\{250:\left[450-\left(2.5^3-2^3.25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-\left(2.125-8.25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-\left(250-200\right)\right]\right\}\)

\(=100:\left\{250:\left[450-50\right]\right\}\)

\(=100:\left\{250:400\right\}\)

\(=100:0,625\)

\(=160\)

 

a: \(2^3\cdot15-\left[115-\left(12-5\right)^2\right]\)

\(=8\cdot15-115+7^2\)

\(=54\)

b: \(100:\left\{250:\left[450-\left(2\cdot5^3-2^3\cdot25\right)\right]\right\}\)

\(=100:\left\{250:\left[450-50\right]\right\}\)

\(=100:\left\{250:400\right\}\)

\(=100:\dfrac{5}{8}=160\)

a) {[(37 + 13) : 5] - 45 : 5} . 7 = {[50 : 5] - 45 : 5} . 7 = {10 - 9} . 7 = 1 . 7 = 7 b) 62 . 10 : {780 : [103 - (2 . 53 + 35 . 14)]} = 36 . 10 : {780 : [1 000 - (2 . 125 + 35 . 14)]} = 36 . 10 : {780 : [1 000 - (250 + 490)]} = 36 . 10 : {780 : [1 000 - 740]} = 36 . 10 : {780 : 260} = 36 . 10 : 3 = 360 : 3 = 120

{50:5-45:5}x7

={10-9}x7

=1x7

=7

d,

=6^2x10:{780:[1000-15,625+35x14]}

=6^2x10:{780:[1000-15,625+490]}

=6^2x10:{780:1474,375}

=6^2x10:0,52903772785

=36x10:0,52903772785

=360:0,52903772785

=608,480769232

khum bt câu d, làm đúng chưa?

chắc sai á

\(62\cdot10:\left\{780:\left[103-\left(2\cdot53+35\cdot14\right)\right]\right\}\)

\(=62\cdot10:\left\{780:\left[103-596\right]\right\}\)

\(=620:\dfrac{-780}{493}\)

\(=620\cdot\dfrac{-493}{780}=\dfrac{-15283}{39}\)

`a)3/5+13/5-5/9-3/7`

`=16/5-5/9-3/7`

`=698/315`

3/5 + 13 /5 -5/9 - 3/7 = 698/315

\(\dfrac{3}{5}+\dfrac{13}{25}-\dfrac{5}{9}-\dfrac{3}{7}\)

\(=\dfrac{15}{25}+\dfrac{13}{25}-\dfrac{35}{63}-\dfrac{27}{63}\)

\(=\dfrac{28}{25}-\dfrac{62}{63}=\dfrac{214}{1575}\)

bằng 214/1575

Bài 1

a) 15 + 4.12 - 3²

=15 + 48 - 9

= 63 - 9

= 54

b) {[(37 + 13) : 5].2 - 45 : 5}.7 - 2022⁰

= [(50 : 5).2 - 9].7 - 1

= (10.2 - 9).7 - 1

= (20 - 9).7 - 1

= 11.7 - 1

= 77 - 1

= 76

Bài 2

a) 13x + 3 = 16

13x = 16 - 3

13x = 13

x = 13 : 13

x = 1

b) 2x - 138 = 2⁴ : 2³

2x = 2 + 138

2x = 140

x = 140 : 2

x = 70

 

Dễ 1+1=2