a,\(\left[\left(-52\right)+18\right].\left(-7\right)\)

\(=\left(-34\right).\left(-7\right)\)

\(=238\)

b,\(\left(18-3.21\right)+\left(-24\right)\)

\(=>\left(18-63\right)-24\)

\(=>-45-24\)

\(=-\left(45+24\right)\)

\(=-69\)

a) [ ( -52) + 18] x ( -7)                              b)(18 -3 x 21) + (-24)

=(-34) x (-7)                                              =(18-63)-24

=238                                             =-69

c)(-40) : 8 + 3 x (21 - 33)                          f) 48 x 15 - 257 x 48

= -5+3 x (-12)                                            =48 x ( 15-257)

= -5-36                                                       =48 x (-242)

= -41                                                          =-11616

đây ạ :v

c,\(\left(-40\right):8+3.\left(21-33\right)\)

\(=-5+3.\left(-12\right)\)

\(=>-5+-36\)

\(=-41\)

f,\(48.15-257.48\)

\(=48.\left(15-257\right)\)

\(=48.\left(-242\right)\)

\(=-11616\)

a) =-34.-7

=238

b) =-45-24

=-69

hacker 2k6

\(a,\left[\left(-52\right)+18\right].\left(-7\right)\)

\(=\left[-52+18\right].\left(-7\right)\)

\(=-34.\left(-7\right)=34.7\)

\(=238\)

\(b,\left(18-3.21\right)+\left(-24\right)\)

\(=\left(18-63\right)-24\)

\(=18-63-24=-69\)

a) [(-52)+18] x (-7)

=-34 x (-7)

=238

b) (18-3 x 21)+(-24)

=(18-63)-24

=-45-24

=-69

c) (-40):8+3x(21-33)

=-5+3 x (-12)

=-5-36

=-41

d) (-4) x 125 x (-25)  x (-6) x (-8)

= [(-4) x (-25)] x [125 x (-8)] x (-6)

= 100 x (-1000) x (-6)

= -10000 x (-6)

=60000

a. -3/4 x 12/-5 x (-25/6)=-15/2

b. -2 x -38/21 x -7/4 x (-3/8)=-19/8

c. (11/12: 33/16) x 3/5=4/15

d. 7/23 x [(-8/6)- 45/18]=-7/6

a. -3/4 x 12/-5 x (-25/6)=-15/2

b. -2 x -38/21 x -7/4 x (-3/8)=-19/8

c. (11/12: 33/16) x 3/5=4/15

d. 7/23 x [(-8/6)- 45/18]=-7/6

Bài 1:

a) 43+45+47+...+565 [có (565-43)/2+1= 262 số hạng)

= [(565+43)*262]/2

= 79648

b) 21+24+27+...+318 [có (318-21)/3+1= 100 số hạng]

= [(318+21)*100]/2

= 16950

mn. giúp em nha 

\(a.\dfrac{6}{5}=\dfrac{18}{x}\Rightarrow x=\dfrac{18\cdot5}{6}=15\\ \text{Vậy}\text{ }x=15.\)

\(b.\dfrac{3}{4}=\dfrac{-21}{x}\Rightarrow x=\dfrac{-21\cdot4}{3}=28\\ \text{ }\text{ }\text{ }\text{ }\text{Vậy }x=28.\)

\(c.\dfrac{x}{4}=\dfrac{21}{28}\Rightarrow x=\dfrac{21\cdot4}{28}=3\\ \text{Vậy }x=3.\)

\(d.\dfrac{-8}{2x}=\dfrac{3}{-9}\Rightarrow x=\dfrac{-8\cdot\left(-9\right)}{3}:2=12\\ \text{Vậy }x=12.\)

\(e.\dfrac{-4}{11}=\dfrac{x}{22}=\dfrac{40}{z}\\ \Rightarrow x=\dfrac{-4\cdot22}{11}=-8\\ \Rightarrow z=\dfrac{22\cdot40}{-8}=-110\\ \text{Vậy }x=-8;z=-110.\)

\(f.\dfrac{-3}{4}=\dfrac{x}{20}=\dfrac{21}{y}\\ \Rightarrow x=\dfrac{-3\cdot20}{4}=-15\\ \Rightarrow y=\dfrac{21\cdot20}{-15}=-28\\ \text{Vậy }x=-15;y=-28.\)

\(g.\dfrac{-4}{8}=\dfrac{x}{-10}=\dfrac{-7}{y}=\dfrac{z}{-24}\\ \Rightarrow x=\dfrac{-4\cdot\left(-10\right)}{8}=5\\ \Rightarrow y=\dfrac{-7\cdot\left(-10\right)}{5}=14\\ \Rightarrow z=\dfrac{-7\cdot\left(-24\right)}{14}=12\\ \text{Vậy }x=5;y=14;z=12.\)

\(h.\dfrac{x}{4}=\dfrac{9}{x}\\ \Rightarrow x\cdot x=9\cdot4\\ \Rightarrow x\cdot x=36\\ \Rightarrow x\cdot x=6\cdot6\\ \text{Vậy }\text{cả hai }x=6.\)

Bài 1: 

a: x/-2=-18/x

=>x²=36

=>x=6 hoặc x=-6

b: x/2+x/5=17/10

=>7/10x=17/10

hay x=17/7

thu gọn 7^3*7^5

Oh no nhiều kí tự đặc biệt quá

dễ quá mình ko làm  đc