Lời giải  đầy đủ:

Bài 3:tìm x

A,

6.(x+9845)=29042.6

(x+9845)=29042.6:6

x+9845=29042

x=29042-9845

x=19197.

B,

(x:3).8=8.3198

(x:3)=3198.8:8

x:3=3198

x=3198.3

x=9594.

Bài 7:

A/191+x+9=43.5

200+x=215

x=215-200

x=15.

B/x.25.4=125.8

x.100=1000

x=1000:100

x=10.

Bài 8:

A/ 128.x-12.x-16.x=5208000

(128-12-16).x=5208000

100.x=5208000

x=5208000:100

x=52080.

B/ x.27+x.30+x.43=210500

x.(27+30+43)=210500

x.100=210500

x=210500:100

x=2105.

K mình nhé!

\(\frac{1}{5.8}+\frac{1}{8.11}+\frac{1}{11.14}+...+\frac{1}{x.\left(x+30+\frac{101}{1540}\right)}\)

Phải gì không .

ghi nham la the nay

1 phan 5 nhan 8 cong 1 phan 8 nhan 11 cong 1 phan 11 nhan 14 +..........+1 phan x nhan (x+3)=101 phan 1540

đs : 2.28571428571 nha

\(30\%\times y+y=104\)

\(\Leftrightarrow0,3\times y+y=104\)

\(\Leftrightarrow1,3y=104\)

\(\Leftrightarrow y=104:1,3\)

\(\Leftrightarrow y=80\)

Vậy \(y=80\)

cam on

`#3107.101107`

\(\left(\dfrac{2}{3}\right)^x+\left(\dfrac{2}{3}\right)^{x+2}=\dfrac{104}{243}?\)

\(\Rightarrow\left(\dfrac{2}{3}\right)^x+\left(\dfrac{2}{3}\right)^x\cdot\left(\dfrac{2}{3}\right)^2=\dfrac{104}{243}\)

\(\Rightarrow\left(\dfrac{2}{3}\right)^x\cdot\left(1+\dfrac{2^2}{3^2}\right)=\dfrac{104}{243}\)

\(\Rightarrow\left(\dfrac{2}{3}\right)^x\cdot\left(1+\dfrac{4}{9}\right)=\dfrac{104}{243}\)

\(\Rightarrow\left(\dfrac{2}{3}\right)^x\cdot\dfrac{13}{9}=\dfrac{104}{243}\)

\(\Rightarrow\left(\dfrac{2}{3}\right)^x=\dfrac{104}{243}\div\dfrac{13}{9}\)

\(\Rightarrow\left(\dfrac{2}{3}\right)^x=\dfrac{8}{27}\)

\(\Rightarrow\left(\dfrac{2}{3}\right)^x=\dfrac{2^3}{3^3}\)

\(\Rightarrow\left(\dfrac{2}{3}\right)^x=\left(\dfrac{2}{3}\right)^3\)

\(\Rightarrow x=3\)

Vậy, `x = 3.`

a)

104 x 7 = 7 x 104

b)

9 x 30 = (20+10) x 9

c)

(6 x 15) x 21 = 6 x (15 x 21)

d)

23 x 3 x 4 = 4 x 69= 12 x 23

Dễ mà bạn          

méo biết

Giúp mình giải bài toán này với. Mình giải theo cách truyền thống giáo viên bảo sai 92-x = 45-16.

a, k ph đc

b,Đặt \(A=...=\left(x+1\right)\left(x+4\right)\left(x+2\right)\left(x+3\right)-24=\left(x^2+5x+4\right)\left(x^2+5x+6\right)-24\)

Đặt x^2+5x+4=t,ta có:

\(A=t\left(t+2\right)-24=t^2+2t-24=t^2-4t+6t-24=t\left(t-4\right)+6\left(t-4\right)=\left(t-4\right)\left(t+6\right)\)

\(=\left(x^2+5x+4-4\right)\left(x^2+5x+4+6\right)=x\left(x+5\right)\left(x^2+5x+10\right)\)

ta có:

(X x 2 + 50) x 5 -200 :10 =30

 (X x 2 + 50) x 5 -200=30 x 10 =300

(X x 2 + 50) x 5 = 300 + 200 = 500

X x 2+50 = 500 : 50=100

X x 2 = 100 - 50= 50

X = 50:2=25