a: =>1170:(x-13)=39

=>x-13=1170/39=30

=>x=43

b: \(\Leftrightarrow x^{1000}\cdot x^{999}-x=0\)

=>\(x\left(x^{1998}-1\right)=0\)

=>\(\left[{}\begin{matrix}x=0\\x^{1998}-1=0\end{matrix}\right.\Leftrightarrow x\in\left\{0;1;-1\right\}\)

1170 : ( x - 13 ) = 339 - 3 * 100

1170 : ( x - 13 ) = 39

             x - 13   = 1170 : 39 

             x - 13    = 30

                     x    = 30 + 13 

                     x     = 43 .

1170-(x-13) = 339 - 3x100

1170 - (x-13) = 339 - 300

1170-(x-13) = 39

x-13 = 1170-39

x-13 = 1131

x = 1131+13 =11 44

1170 : (x - 13) = 339 - 3 . 10²

1170 : (x -13) = 339 - 3 . 100

1170 : (x  -13) = 339 - 300

1170 : (x - 13) = 39

            x - 13 = 1170 : 39 

            x - 13 = 30

            x = 30 + 13

            x = 43

vậy x = 43

ủng hô mk nha

\(1170\div\left(x-13\right)=339-3.100\)

\(1170\div\left(x-13\right)=339-300\)

\(1170\div\left(x-13\right)=39\)

\(x-13=1170\div39\)

\(x-13=30\)

\(x=30+13\)

\(x=43\)

\(Vay\)\(x=43\)

\(3(x-9)+15=12+243:3^2\)

=> 3x - 27 + 15 = 12 + 243 : 9

=> 3x - 27 + 15 = 12 + 27

=> 3x - 27 + 15 = 39

=> 3x - 27 = 39 - 15

=> 3x - 27 = 24

=> 3x = 24 + 27

=> 3x = 51

=> x = 51 : 3 = 17

Vậy x = 17

\(1170:(x-13)=339-3\cdot10^2\)

=> 1170 : [x-13] = 339 - 3 . 100

=> 1170 : [x - 13] = 339 - 300

=> 1170 : [x-13] = 39

=> x - 13 = 30

=> x = 43

a) 3 ( x - 9 ) + 15 = 12 + 243 : 3²

3 ( x - 9 ) + 15 = 12 + 27

3 ( x - 9 ) + 15 = 39

3 ( x - 9 ) = 39 - 15

3 ( x - 9 ) = 24

x - 9 = 24 : 3

x - 9 = 8

x = 8 + 9

x = 17

Vậy x = 17

b) 1170 : ( x - 13 ) = 339 - 3 . 10²

1170 : ( x - 13 ) = 339 - 300

1170 : ( x - 13 ) = 39

x - 13 = 1170 : 39

x - 13 = 30

x = 30 + 13

x = 43

Vậy x = 43

=))

3.(x-9)+15=12+243:\(3^2\)

3.(x-9)+15=12+243:9

3.(x-9)+15=12+27

3.(x-9)+15=39

3.(x-9)=24

x-9=24:3

x-9=8

x=17

Vậy x=17

1170:(x-13)=339-3.\(10^2\)

1170:(x-13)=339-3.100

1170:(x-13)=339-300

1170:(x-13)=39

x-13=1170:39

x-13=30

x=30+13=43

Vậy x=43

a)=>3x=33

=>x=11

b)x²⁰⁰=x

=>x²⁰⁰-x=0

=>x(x¹⁹⁹-1)=0=>x=0 hoặc x=1

c)=>1170:(x-13)=339-300=39

=>x-13=1170:39=30

=>x=43

d)=>7x=28

=>x=4

a,  1170 : x - 13 = 339 . 3 . 10 2

1170:(x - 13) = 339 - 3.100

1170:(x - 13) = 39

x - 13 = 1170:39 = 30 

x = 30+13 = 43

b,  3 x - 9 + 15 = 12 + 243 : 3 2

3(x - 9) + 15 = 12+243:9

3(x - 9)+15 = 12+27

3(x - 9)+15 = 39

3(x - 9) = 24

x  - 9 = 8

x = 17

a: Sửa đề; \(A=\dfrac{7.2:2\cdot28.6+1.43\cdot2\cdot64}{1+3+5+7+...+49-339}\) 

\(=\dfrac{3.6\cdot28.6+2.86\cdot64}{1+3+5+...+49-339}\)

\(=\dfrac{2.86\left(64+36\right)}{25^2-339}=\dfrac{286}{286}=1\)

b: =>2(x+7/8)=6*13/4=78/4=39/2

=>x+7/8=39/4

=>x=71/8

14 . 99 = 1386.

Đáp án: C

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

\(---\)

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

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

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

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

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

\(=2\cdot1001\)

\(=2002\)

\(---\)

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

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

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

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

\(=300-200\)

\(=100\)

#\(Toru\)

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