K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

27 tháng 9 2021

236 - x = 3.2 - 2.3 + 51 : 17

236 - x = 6 - 6 + 3

236 - x = 3

x = 236 - 3

x = 233

~ HT ~

27 tháng 9 2021

Tìm số tự nhiên xx thỏa mãn: 236 - x = 3.2^4- 2.3^2 + 51 : 17236−x=3.24−2.32+51:17.

30 tháng 9 2021

A=\(2^2-9^3+4^{-2}.16-2.5^2\)
\(=4-729+1-50=-774\)
B=\(\left(2^3.2\right).\dfrac{1}{2}+3^{-2}.3^2-7.1+5\)
\(B=2^4.\dfrac{1}{2}+1-7+5=8+1-7+5=7\)
 

16 tháng 8 2024

 C = 2-3 + (52)3.5-3 + 4-3.16 - 2.32 - 105.(\(\dfrac{24}{51}\))0

C =  \(\dfrac{1}{8}\) + 56.5-3 + 4-3.42 - 2.9 - 105.1

C =  \(\dfrac{1}{8}\) + 53\(\dfrac{1}{4}\) - 18 - 105

C =  (\(\dfrac{1}{8}\) + \(\dfrac{1}{4}\))  - (105 - 125 + 18)

C = \(\dfrac{3}{8}\) - (-20 + 18)

C = \(\dfrac{3}{8}\)  + 2

C = \(\dfrac{19}{8}\)

14 tháng 6 2017

Giải:

a) Ta có:

\(\left(9x+5y\right)⋮17\Rightarrow4\left(9x+5y\right)⋮17\)

Hay \(\left(36x+20y\right)⋮17.\)\(34x⋮17;17y⋮17\)

\(\Rightarrow36x+20y-34x-17y=\left(2x+3y\right)⋮17\)

Vậy \(\left(2x+3y\right)⋮17\Leftrightarrow\left(9x+5y\right)⋮17\) (Đpcm)

b) Ta có:

\(\left(a+4b\right)⋮13\Rightarrow10\left(a+4b\right)⋮13\)

\(\Rightarrow10a+40b=\left(10a+b+39b\right)⋮13\)

\(39b⋮13\Rightarrow\left(10a+b\right)⋮13\) (Đpcm)

c) Ta có:

\(\left(10a+b\right)⋮17\Rightarrow2\left(10a+b\right)⋮17\)

Hay \(\left(20a+2b\right)⋮17.\)\(\left(3a+2b\right)⋮17\)

\(\Rightarrow\left(20a+2b\right)-\left(3a+2b\right)=17a⋮17\)

\(\Rightarrow\) Đpcm

`#3107`

b)

`2.3^x = 162`

`\Rightarrow 3^x = 162 \div 2`

`\Rightarrow 3^x = 81`

`\Rightarrow 3^x = 3^4`

`\Rightarrow x = 4`

Vậy, `x = 4`

c)

`(2x - 15)^5 = (2 - 15)^3`

\(\Rightarrow \)`(2x - 15)^5 - (2x - 15)^3 = 0`

\(\Rightarrow \)`(2x - 15)^3 . [ (2x - 15)^2 - 1] = 0`

\(\Rightarrow\left[{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2=1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=15\\\left(2x-15\right)^2=\left(\pm1\right)^2\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x-15=1\\2x-15=-1\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\2x=16\\2x=-14\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=8\\x=-7\end{matrix}\right.\)

Vậy, `x \in`\(\left\{-7;8;\dfrac{15}{2}\right\}.\)

`d)`

\(3^{x+2}-5.3^x=?\) Bạn ghi tiếp đề nhé!

`e)`

\(7\cdot4^{x-1}+4^{x-1}=23?\)

\(4^{x-1}\cdot\left(7+1\right)=23\\ \Rightarrow4^{x-1}\cdot8=23\\ \Rightarrow4^{x-1}=\dfrac{23}{8}\)

Bạn xem lại đề!

`f)`

\(2\cdot2^{2x}+4^3\cdot4^x=1056\)

\(\Rightarrow2\cdot2^{2x}+\left(2^2\right)^3\cdot\left(2^2\right)^x=1056\\ \Rightarrow2\cdot2^{2x}+2^6\cdot2^{2x}=1056\\ \Rightarrow2^{2x}\cdot\left(2+2^6\right)=1056\\ \Rightarrow2^{2x}\cdot66=1056\\ \Rightarrow2^{2x}=1056\div66\\ \Rightarrow2^{2x}=16\\ \Rightarrow2^{2x}=2^4\\ \Rightarrow2x=4\\ \Rightarrow x=2\)

Vậy, `x = 2`

_____

\(10 -{[(x \div 3+17) \div 10+3.2^4] \div 10}=5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=10-5\)

\(\Rightarrow\left[\left(x\div3+17\right)\div10+48\right]\div10=5\)

\(\Rightarrow\left(x\div3+17\right)\div10+48=50\)

\(\Rightarrow\left(x\div3+17\right)\div10=2\)

\(\Rightarrow x\div3+17=20\)

\(\Rightarrow x\div3=3\\ \Rightarrow x=9\)

Vậy, `x = 9.`

a: =>3x-15-2x+6=51

=>x-9=51

=>x=60

b: =>432-2x+22+3x-15=200

=>x+439=200

=>x=-239

c: =>3x+17-4x+13=0

=>30-x=0

=>x=30

d: =>x-3-3x+6=-11-21=-32

=>-2x+3=-32

=>-2x=-35

=>x=35/2

31 tháng 7 2023

\(3\cdot\left(x-5\right)-2\cdot\left(x-3\right)=51\)

\(\Rightarrow3x-15-2x+6=51\)

\(\Rightarrow x-9=51\)

\(\Rightarrow x=51+9\)

\(\Rightarrow x=60\)

b) \(432-2\cdot\left(x-11\right)+3\cdot\left(x-5\right)=200\)

\(\Rightarrow432-2x+22+3x-15=200\)

\(\Rightarrow x+439=200\)

\(\Rightarrow x=200-439\)

\(\Rightarrow x=-239\)

c) \(3x+17=4x-13\)

\(\Rightarrow4x-3x=17+13\)

\(\Rightarrow x=30\)

d) \(\left(x-3\right)+21=3\cdot\left(x-2\right)-11\)

\(\Rightarrow x-3+21=3x-6-11\)

\(\Rightarrow x+18=3x-17\)

\(\Rightarrow3x-x=18+17\)

\(\Rightarrow2x=35\)

\(\Rightarrow x=\dfrac{35}{2}\)

a: \(=\dfrac{18}{51}\cdot\dfrac{34}{9}\cdot\dfrac{17}{18}=\dfrac{17}{51}\cdot\dfrac{34}{9}=\dfrac{1}{3}\cdot\dfrac{34}{9}=\dfrac{34}{27}\)

b: \(=\dfrac{21}{32}\cdot\dfrac{4}{7}\cdot25\cdot\dfrac{4}{5}=\dfrac{21}{7}\cdot\dfrac{4}{32}\cdot20=60\cdot\dfrac{1}{8}=\dfrac{15}{2}\)

7 tháng 3 2018

a(17/4x12/7-2/7x17/4-3/7x17/4)x6/51

=[17/4x(12/7-2/7-3/7)]x6/51

=17/4x1x6/51

=17/4x6/51

=102/204=1/2

b,45x16-17/45x15+28

=15x3x16-17/45x15+28

=15x48-17/45x15+28

=15x2160/45-17/45x15+28

=15x(2160/45-17/45)+28

=15x2143/45+28

=2143/3+84/3

=2227/3

20 tháng 1 2022

tính nhanh à,lên google search í

  (Người THÀNH CÔNG luôn có một lối đi riêng)

23 tháng 11 2021

\(\dfrac{33}{38}:\dfrac{11}{19}=\dfrac{33\times19}{38\times11}=\dfrac{3\times1}{2\times1}=\dfrac{3}{2}\)

7 tháng 11 2024

3phần2