K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Các câu hỏi dưới đây có thể giống với câu hỏi trên
21 tháng 7 2023
1: x=3/4-1/2=3/4-2/4=1/4
2: x-1/5=2/11
=>x=2/11+1/5=21/55
3: x-5/6=16/42-8/56
=>x-5/6=8/21-4/28=5/21
=>x=5/21+5/6=15/14
4: x/5=5/6-19/30
=>x/5=25/30-19/30=6/30=1/5
=>x=1
5: =>|x|=1/3+1/4=7/12
=>x=7/12 hoặc x=-7/12
6: x=-1/2+3/4
=>x=3/4-1/2=1/4
11: x-(-6/12)=9/48
=>x+1/2=3/16
=>x=3/16-1/2=-5/16
21 tháng 7 2023
1)x= 1/4
2)x= 2/11+ 1/5
x= 21/55
3)x - 5/6 = 5/21
x = 5/21+5/6
x = 15/14
4)x/5 = 5/6 + -19/30
x:5 = 1/5
x = 1/5.5
x = 1
5) |x| - 1/4 = 6/18
|x| = 6/18 - 1/4
|x| =7/12
⇒x= 7/12 hoặc -7/12
6)x = -1/2 +3/4
x= 1/4
7) x/15 = 3/5 + -2/3
x:15 = -1/15
x = -1/15. 15
x = -1
8)11/8 + 13/6 = 85/x
85/24 = 85/x
⇒ x = 24
9) x - 7/8 = 13/12
x = 13/12 + 7/8
x = 47/24
10)x - -6/15 = 4/27
x = 4/27 + (-6/15)
x = -34/135
11) -(-6/12)+x = 9/48
x= 9/48 - 6/12
x = -5/16
12) x - 4/6 = 5/25 + -7/15
x -4/6 = -4/15
x = -4/15 + 4/6
x = 2/5
HD
2
27 tháng 6 2017
A)\(\left(4-\frac{8}{3}\right)x\frac{15}{7}-\frac{8}{5}:\frac{1}{10}\)
\(=\frac{4}{3}x\frac{15}{7}-\frac{8}{5}x\frac{1}{10}\)
\(=\frac{20}{7}-\frac{4}{25}\)
\(=\frac{222}{185}\)
B)\(\frac{7}{5}x\frac{3}{8}+\frac{7}{5}x\frac{5}{8}-\frac{37}{5}\)
\(=\frac{7}{5}x\left(\frac{3}{8}+\frac{5}{8}\right)-\frac{37}{5}\)
\(=\frac{7}{5}x1-\frac{37}{5}\)
\(=\frac{7}{5}-\frac{37}{5}\)
\(=\frac{-30}{5}
\)
\(=-6\)
LA
27 tháng 6 2017
A =\(\left(4-\frac{8}{3}\right).\frac{15}{7}-\frac{8}{5}:\frac{1}{10}\)
\(=\frac{4}{3}.\frac{15}{7}-16\)
\(=\frac{20}{7}-\frac{112}{7}\)
\(=\frac{-92}{7}\)
B\(=\frac{7}{5}.\frac{3}{8}+\frac{7}{5}.\frac{5}{8}-\frac{37}{5}\)
\(=\frac{7}{5}.\left(\frac{3}{8}+\frac{5}{8}\right)-\frac{37}{5}\)
\(=\frac{7}{5}-\frac{37}{5}\)
\(=-6\)
NN
1
KM
11 tháng 7 2015
Bài 1:
\(\left(-0,125\right)\times7,9\times80\)
\(=\left(-0,9875\right)\times80\)
\(=79.\)
\(\left(0,125\right)\times1\times0,25\times8\times\left(-4\right)\)
\(=0,125\times0,25\times8\times\left(-4\right)\)
\(=0,03125\times8\times\left(-4\right)\)
\(=0,25\times\left(-4\right)\)
\(=\left(-1\right).\)
Bài 2:
\(x+\frac{8}{3}^2=\frac{1}{9}\)
\(x+16=\frac{1}{9}\)
\(x=\frac{1}{9}-16.MSC=9\)
\(x=\frac{1}{9}-\frac{144}{9}\)
\(x=\frac{-143}{9}.\)
7 tháng 10 2021
Bài 1:
a) \(=\dfrac{8}{15}\left(\dfrac{7}{13}+\dfrac{6}{13}\right)=\dfrac{8}{15}.1=\dfrac{8}{15}\)
b) \(=\dfrac{3.3-7-2.4}{12}=-\dfrac{6}{12}=-\dfrac{1}{2}\)
Bài 2:
\(\dfrac{x}{2,7}=-\dfrac{2}{3,6}\Rightarrow x=\dfrac{\left(-2\right).2,7}{3,6}\Rightarrow x=-\dfrac{3}{2}\)
Bài 3:
\(\dfrac{x}{2}=\dfrac{y}{5}=\dfrac{x+y}{2+5}=-\dfrac{21}{7}=-3\)
\(\Rightarrow\left\{{}\begin{matrix}x=\left(-3\right).2=-6\\y=\left(-3\right).5=-10\end{matrix}\right.\)
VM
28 tháng 10 2019
1.
b) \(3^x+3^{x+2}=2430\)
\(\Rightarrow3^x.1+3^x.3^2=2430\)
\(\Rightarrow3^x.\left(1+3^2\right)=2430\)
\(\Rightarrow3^x.10=2430\)
\(\Rightarrow3^x=2430:10\)
\(\Rightarrow3^x=243\)
\(\Rightarrow3^x=3^5\)
\(\Rightarrow x=5\)
Vậy \(x=5.\)
c) \(\left(2x-15\right)^5=\left(2x-15\right)^3\)
\(\Rightarrow\left(2x-15\right)^5-\left(2x-15\right)^3=0\)
\(\Rightarrow\left(2x-15\right)^3.\left[\left(2x-15\right)^2-1\right]=0\)
\(\Rightarrow\left[{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x-15=0\\\left(2x-15\right)^2=1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}2x=15\\2x-15=\pm1\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=15:2\\2x-15=1\\2x-15=-1\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{15}{2}\\2x=16\\2x=14\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{15}{2}\\x=8\\x=7\end{matrix}\right.\)
Vậy \(x\in\left\{\frac{15}{2};8;7\right\}.\)
Chúc bạn học tốt!
17 tháng 2 2020
\(/x-\frac{1}{2}/=\frac{1}{3}\\ =>\orbr{\begin{cases}x-\frac{1}{2}=\frac{1}{3}\\x-\frac{1}{2}=-\frac{1}{3}\end{cases}}\\ =>\orbr{\begin{cases}x=\frac{1}{3}+\frac{1}{2}\\x=-\frac{1}{3}+\frac{1}{2}\end{cases}}\\ =>\orbr{\begin{cases}x=\frac{5}{6}\\x=\frac{1}{6}\end{cases}}\)
17 tháng 2 2020
\(a,|x-\frac{1}{2}|=\frac{1}{3}\)
\(\Rightarrow\orbr{\begin{cases}x-\frac{1}{2}=\frac{1}{3}\\x-\frac{1}{2}=-\frac{1}{3}\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{5}{6}\\x=\frac{1}{6}\end{cases}}}\)
\(b,\frac{14}{15}:\frac{9}{10}=x:\frac{3}{7}\)
\(\frac{28}{27}=x:\frac{3}{7}\)
\(x=\frac{4}{9}\)
A
0
\(\left|\frac{-2}{3}x+\frac{3}{8}\right|\left(-\frac{8}{5}\right)=\frac{-8}{15}\)
\(\left|\frac{-2}{3}x+\frac{3}{8}\right|=\frac{-8}{15}:\frac{-8}{15}\)
\(\left|\frac{-2}{3}x+\frac{3}{8}\right|=1\)
\(\Rightarrow-\frac{2}{3}x+\frac{3}{8}\in\left\{1;-1\right\}\)
\(\Rightarrow-\frac{2}{3}x\in\left\{\frac{5}{8};\frac{-11}{8}\right\}\)
\(\Rightarrow x\in\left\{\frac{-15}{16};\frac{33}{16}\right\}\)