mình còn ko bt cơ mà mai nộp r

mik chỉ lm đc 1 câu thôi mong bn like cho
(13911:3849−5211:3849):(4938.511)={(13+911).4938−(5+211).4938}:(4938.511)=4938.(13−5+911−211):(4938.511)=4938.(8+711):(4938.511)=(8+711):511=19

1: \(=\dfrac{-5}{8}\cdot\dfrac{15}{4}=-\dfrac{75}{32}\)

2: \(=\dfrac{15}{17}\cdot\dfrac{25}{34}=\dfrac{375}{578}\)

3: \(=-12\cdot\dfrac{8}{3}=-4\cdot8=-32\)

4: \(=\dfrac{15}{14}\cdot\dfrac{20}{21}=\dfrac{50}{49}\)

5: \(=48\cdot\dfrac{24}{5}=230.4\)

Bạn tự tính dần dần ( dùng các cách tính nhanh )

=> Kết quả

\(\left(\dfrac{6:\dfrac{3}{5}-\dfrac{17}{16}.\dfrac{6}{7}}{\dfrac{21}{5}.\dfrac{10}{11}+\dfrac{57}{11}}-\dfrac{\left(\dfrac{3}{20}+\dfrac{1}{2}-\dfrac{1}{15}\right).\dfrac{12}{49}}{\dfrac{10}{3}+\dfrac{2}{9}}\right).x=\dfrac{215}{96}\)

\(\Rightarrow\left(\dfrac{\dfrac{509}{56}}{9}-\dfrac{\dfrac{7}{12}.\dfrac{12}{49}}{\dfrac{32}{9}}\right).x=\dfrac{215}{96}\)

\(\Rightarrow\left(\dfrac{509}{504}-\dfrac{\dfrac{1}{7}}{\dfrac{32}{9}}\right).x=\dfrac{215}{96}\)

\(\Rightarrow\left(\dfrac{509}{504}-\dfrac{9}{224}\right).x=\dfrac{215}{96}\)

\(\Rightarrow\dfrac{1955}{2016}.x=\dfrac{215}{96}\)

\(\Rightarrow x=\dfrac{215}{96}:\dfrac{1955}{2016}\)

\(\Rightarrow x=\dfrac{903}{391}\)

`[ 6 : 3/5 - 17/16 . 6/7 : 21/5 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 :  10/3 + 2/9 ] . x = 215/96`

`=>[ 6  . 5/3 - 17/16 . 6/7 . 5/21 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=>[10- 51/56 . 6/7 . 5/21 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=> [10- 153/196  . 5/21 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=> [10- 255/1372 . 10/11 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=> [10- 1275/7546 + 57/11 -  (3/20 + 1/2 - 1/15) . 12/49 . 3/10 + 2/9 ] . x = 215/96`

`=> (10- 1275/7546 + 57/11 -  7/12. 12/49 . 3/10 + 2/9 ) . x = 215/96`

`=> ( 10- 1275/7546 + 57/11 -343/600 . 3/10 + 2/9 ) . x = 215/96`

`=> ( 10- 1275/7546 + 57/11 -343/2000 + 2/9 ) . x = 215/96`

`=>15,06357671 . x= 215/96`

`=> x= 215/96: 15,06357671`

`=>x= 0,1486754027`

Đề có phải như vậy không nhỉ ?

Đáp án cần chọn là: B

Ta có:(−17)+(−|−173|)=(−17)+(−173)=−(17+173)=−190

*Note: Tích của một số với 0 luôn bằng 0.

a) \(\left(1763+7634+23\cdot764\right)\cdot\left(346\cdot45-173\cdot90\right)\)

\(=\left(1763+7634+23\cdot764\right)\cdot\left(346\cdot45-173\cdot45\cdot2\right)\)

\(=\left(1763+7634+23\cdot764\right)\cdot\left(346\cdot45-346\cdot45\right)\)

\(=\left(1763+7634+23\cdot764\right)\cdot0\)

\(=0\)

b) \(N=10\cdot12\cdot14\cdot16\cdot\left(88\cdot17-44\cdot34\right)\)

\(N=10\cdot12\cdot14\cdot16\cdot\left(88\cdot17-44\cdot17\cdot2\right)\)

\(N=10\cdot12\cdot14\cdot16\cdot\left(88\cdot17-88\cdot17\right)\)

\(N=10\cdot12\cdot14\cdot16\cdot0\)

\(N=0\)

c) \(\left(80\cdot96+40\cdot1808\right):1000\)

\(=\left(80\cdot96+40\cdot904\cdot2\right):1000\)

\(=\left(80\cdot96+80\cdot904\right):1000\)

\(=\left[80\cdot\left(96+904\right)\right]:1000\)

\(=80\cdot1000:1000\)

\(=80\)

16) M = (-32 + 215) - (-30 + 215)

= -32 + 215 + 30 - 215

= (215 - 215) + (30 - 32)

= 0 - 2 = -2

17) N = -5 + (-37 - 45 + 151) - (-37 + 151)

= -5 - 37 - 45 + 151 + 37 - 151

= (151 - 151) - (5+45) + (37 - 37)

= 0 - 50 + 0 = -50

a. -20+5=-15 

b. 7

c. 35 + (-4)= 31 

d. -129-37+29-63= -100-100 = -200 

e. 217 -315-117+215 =100-100=0 

f. 15:(-3)+24:2 = -5 + 12 = 7 

g. (-5).(-7)-3.(14)= 35 - 42 = -7 

H. (-15)x(-129+29) = -15 x -100 =1500 

i. 13 x (-125+25) =13 x -100 = -1300 

k. 37(-135+35) = 37 x -100 = -3700