trình bày chi tiết với ạ;-;

\(=23\cdot15-115+13=243\)

= 23 . 15 - ( 115 - 13 )

= 345 - 102 = 243

\(23.15-[115+\left(12-25\right)]\)
\(345-[115+\left(-13\right)]\)
\(345-102=243\)

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

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

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

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

Mik làm 1 câu thôi sức ko

\(2^3.15-\left[115-\left(12-5\right)^2\right]=8.15-\left[115-7^2\right]=120-\left[115-49\right]=120-66=54\)

\(100:\left\{250:\left[450-\left(4.5^3-2^2.25\right)\right]\right\}=100:\left\{250:\left[450-\left(4.125-4.25\right)\right]\right\}=100:\left\{250:\left[450-\left(500-100\right)\right]\right\}\)

\(=100:\left[250:\left(450-400\right)\right]=100:\left(250:50\right)=100:5=20\)

a,2³ . 15 -[115-\((\)12-5)²]

= 8. 15 - [115- 7² ]

=120-[115-49]

=120-66

=54

b, 100:{250:[450-\((\)4.5³ - 2³.25)]}

=100:{250:[450-\((\)4.125-8.25)]}

=100:{250:[450-\((\)500-300)]}

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

=100:{250:250}

=100:1

=100

a)3⁶:3²+2³.2²-3³.3 

= 3⁴+2⁵-3⁴

=2⁵

=32

b)3⁸:3⁴-9⁵:9³

= 3⁴-9²

= 3⁴-3⁴

= 0

c)2³.15+2³.35

= 2³(15+35)

= 8.50

= 400

a: \(3^6:3^2+2^3\cdot2^2-3^3\cdot3\)

\(=3^4+32-3^4\)

=32

b: \(3^8:3^4-9^5:9^3\)

\(=3^4-9^2\)

=0

c: Ta có: \(2^3\cdot15+2^3\cdot35\)

\(=8\cdot50\)

=400

\(a)2^3\cdot15-[115-(12-5)^2]\\=8\cdot15-(115-7^2)\\=120-(115-49)\\=120-66\\=54\\---\\b)5\cdot[(85-35:7):8+90]-60\\=5\cdot[(85-5):8+90]-60\\=5\cdot(80:8+90)-60\\=5\cdot(10+90)-60\\=5\cdot100-60\\=500-60\\=440\)

\(---\)

\(c,\left\{\left[261-\left(36-31\right)^3\cdot2\right]-9\right\}\cdot1001\)

\(=\left[\left(261-5^3\cdot2\right)-9\right]\cdot1001\)

\(=\left[\left(261-125\cdot2\right)-9\right]\cdot1001\)

\(=\left[\left(261-250\right)-9\right]\cdot1001\)

\(=\left(11-9\right)\cdot1001\)

\(=2\cdot1001\)

\(=2002\)

\(---\)

\(d,3\cdot10^2-\left[1200-\left(4^2-2\cdot3\right)^3\right]\)

\(=3\cdot100-\left[1200-\left(16-6\right)^3\right]\)

\(=300-\left(1200-10^3\right)\)

\(=300-\left(1200-1000\right)\)

\(=300-200\)

\(=100\)

#\(Toru\)

a) 2³.15 -[115-(12-5)² ]

= 2³.15 -[115-36]

= 8.15 -79

= 120-79

=41

b)5.[(85 - 35 : 7) :8 + 90 ] - 50

=5 .[80:8+90]-50

=5.100-50

=500-50

=450

c){[261 - ( 36-31)³.2 ]-9}.1001

={[261 - 125.2 ]-9}.1001

={[261 -250 ]-9}.1001

={11-9}.1001

=2.1001

=2002

d)3.10² - [1200 - ( 4² - 2.3)^3]

=3.100-[1200 -(16-6)³ ]

=300-[1200-1000]

=300-200

=100

Bài 1: 

a: =25+75=100

b: =60-17-43+12=12

c: =-2-18=-20

d: =-3+36-17=36-20=16

Bài 2: 

a: =-102

b: =-1000

c: =12x15=180

d: =21x(-10)=-210

B1

a 100

b 12

c -20

d 16

B2

a -102

b -1000

c 180

d -210

Bài 1:Tính

 a)(-12)+25+75+12 = 100

b)60+12+(-17)+(-43)=12
c)(-2)+(-87)+(-18)+87=-20
d)(-1)+(-2)+36+(-17)=16
Bài 2:Tính
b)8 . (-125)=-100
c)(-12) . (-15)=180
d)21 . (- 3)+(- 21 ) . 7=-210

a \(\dfrac{3}{2}\)

b \(\dfrac{8}{3}\)

a) \(\dfrac{5}{12}+\dfrac{3}{4}+\dfrac{1}{3}=\dfrac{5}{12}+\dfrac{9}{12}+\dfrac{4}{12}=\dfrac{18}{12}=\dfrac{3}{2}\)

b) \(\dfrac{4}{9}+\dfrac{25}{18}+\dfrac{5}{6}=\dfrac{8}{18}+\dfrac{25}{18}+\dfrac{15}{18}=\dfrac{48}{18}=\dfrac{8}{3}\)