7 x 17 x 125 = (8 x 125) x 17 = 1000 x 17 = 17000

4 x 37 x 25 = (25 x 4 ) x 7 = 100 x 7 = 700

43 x 27 + 93 x 43 + 57 x 81 + 69 x 57 = 43 x (27 + 93) + 57 x (81 +69) = 43 x 120 + 57 x 120 + 57x30 = 120 x (43 + 57) + 1710 = 12000 + 1710 = 13710 

     43 x 27 + 93 x 43 + 57 x 61 + 59 x 57 

  = 43 x ( 27 + 93 ) + 57 x ( 61 + 59 )

  =  43 x 120 +  57 x 120

  = 120 x ( 43 + 57 )

   = 120 x 100

  = 1200

b) 64 x 6 + 81 x 4 + 17 x 6 

 = 6 x ( 64 + 17 ) + 81 x 4 

 =  6 x 81 + 81 x 4 

 = 81 x ( 6 + 4 ) 

 = 81 x 10 

 = 810

A) =43 x (27+93)+57*(61+59)

=43*120+57*120

=120*(43+57)

=120*100

=12000

\(43\times7+93\times43+57\times61+69\times57\)

\(=43\times\left(7+43\right)+57\times\left(61+69\right)\)

\(=43\times50+57\times130\)

\(=2150+7410\)

\(=9560\)

\(9560\)

\(e,112-45+5x=87\)

\(67+5x=87\)

\(5x=20\)

\(x=4\)

\(f,6^2+64:\left(x-1\right)=52\)

\(36+64:\left(x+1\right)=52\)

\(64:\left(x+1\right)=16\)

\(x+1=4\)

\(x=3\)

\(g,\left(55-x\right)\left(2x-44\right)=0\)

\(\Rightarrow\hept{\begin{cases}55-x=0\\2x-44=0\end{cases}}\)

\(\Rightarrow\hept{\begin{cases}x=55\\x=22\end{cases}}\)

Vậy ....

\(h,x^2+4=13\)

\(x^2=9\)

\(x^2=\pm3^2\)

\(\Rightarrow x=\pm3\)

\(i,2\left(x+1\right)^3=16\)

\(\left(x+1\right)^3=8\)

\(\left(x+1\right)^3=2^3\)

\(\Rightarrow x+1=2\)

\(x=1\)

\(g,150-5\left(x-2\right)^2=25\)

\(5\left(x-2\right)^2=125\)

\(\left(x-2\right)^2=25\)

\(\left(x-2\right)^2=\pm5^2\)

\(\Rightarrow\hept{\begin{cases}x-2=5\\x-2=\left(-5\right)\end{cases}\Rightarrow\hept{\begin{cases}x=7\\x=\left(-3\right)\end{cases}}}\)

Vậy .... 

2x + x - 12 = 0

=> 3x = 12

=> x = 4

vậy_

2x + x - 12 = 0

2x + x = 0 + 12

2x + x = 12

3x = 12

x= 12 : 3

x = 4

64 .6 + 81 . 4 + 17 . 6

= 6 . ( 64 + 17 ) + 81 . 4

= 6 . 91 + 81 . 4

= 546 + 324

= 870 

43 . 27 + 93 . 43 + 57 . 61 + 59 . 57

= ngày mai giải tiếp, đi ngủ đã !!!-_-^zzz

2x + x - 12 = 0 

<=> 2x + 1x - 12 = 0 

<=> 3x - 12 = 0 

<=> 3x = 0 + 12 

<=> 3x = 12 

<=> x = 12 : 3 

<=> x = 4

Vậy x = 4 

64 . 6 + 81 . 4 + 17 . 6 

= 64 . 6 + 17 . 6 + 81 . 4 

= 6 . ( 64 + 17 ) + 81 . 4 

= 6 . 81 + 81 . 4 

= 81 . ( 6 + 4 ) 

= 81 . 10 

= 810 

43 . 27 + 93 . 43 + 57 . 61 + 59 . 57 

= 43 . ( 27 + 93 ) + 57 . ( 61 + 59 ) 

= 43 . 129 + 57 . 120 

= 120 . ( 43 + 57 ) 

= 120 . 100 

= 12 000

1.

$\sqrt{3x^2}-\sqrt{12}=0$

$\Leftrightarrow \sqrt{3x^2}=\sqrt{12}$

$\Leftrightarrow 3x^2=12$

$\Leftrightarrow x^2=4$

$\Leftrightarrow (x-2)(x+2)=0\Leftrightarrow x=\pm 2$

2. 

$\sqrt{(x-3)^2}=9$

$\Leftrightarrow |x-3|=9$

$\Leftrightarrow x-3=9$ hoặc $x-3=-9$

$\Leftrightarrow x=12$ hoặc $x=-6$

3.

$\sqrt{4x^2+4x+1}=6$

$\Leftrightarrow \sqrt{(2x+1)^2}=6$

$\Leftrightarrow |2x+1|=6$

$\Leftrightarrow 2x+1=6$ hoặc $2x+1=-6$

$\Leftrightarrow x=\frac{5}{2}$ hoặc $x=\frac{-7}{2}$

\(8,64\times93+8,64:0,5+8,64:0,25+8,64\)

\(=8,64\times93+8,64\times2+8,64\times4+8,64\times1\)

\(=8,64\times\left(92+4+2+1\right)\)

\(=8,64\times100\)

\(=864\)

giúp mh với mh đang cần gấp 

hứa mh sẽ tích

7 x 4 + 32 = 28 + 32    7 x 7 + 28 = 49 + 28

    = 60       = 77

7 x 8 – 16 = 56 – 16    7 x 9 – 57 = 63 – 57

   = 40       = 6.

a) (x.7 + 8) : 5 = 10

x.7 + 8 = 10.5

x.7 + 8 = 50

x.7 = 50 - 8

x.7 = 42

x = 42 : 7

x = 6

b) (x + 5).19 : 13 = 57

(x + 5).19 = 57 . 13

(x + 5).19 = 741

x + 5 = 741 : 19

x + 5 = 39

x = 39 - 5

x = 34

c) 4.(36 - 4.x) = 64

36 - 4x = 64 : 4

36 - 4x = 16

4x = 36 - 16

4x = 20

x = 20 : 4

x = 5

d) 7,6 : 19 . x = 3,2

0,4 . x = 3,2

x = 3,2 : 0,4

x = 8

e) (x : 2 + 50) : 5 = 12

x : 2 + 50 = 12 . 5

x : 2 + 50 = 60

x : 2 = 60 - 50

x : 2 = 10

x = 10 . 2

x = 20

g) 280 : (17 + 3.x) = 4

17 + 3x = 280 : 4

17 + 3x = 70

3x = 70 - 17

3x = 53

x = 53/3

h) 6.(28 - 8.x) = 72

28 - 8x = 72 : 6

28 - 8x = 12

8x = 28 - 12

8x = 16

x = 16 : 8

x = 2

i) (x - 15) : 3 : 12 = 6

(x - 15) : 3 = 6 . 12

(x - 15) : 3 = 72

x - 15 = 72 . 3

x - 15 = 216

x = 216 + 15

x = 231