tìm x
\(\left|2x-\frac{1}{3}\right|+\frac{5}{6}=1\)
\(\frac{7}{9}:\left(2+\frac{3}{4}x\right)+\frac{5}{9}=\frac{23}{27}\)
giúp mk nha , ngày mai cô mk kiểm tra mấy câu này , không có là mk "xơi" trứng ngỗng đấy
K
Khách
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HM
3
Những câu hỏi liên quan
. Chú ý dấu chấm là nhân nha.
3 tháng 2 2022
a: \(=2016+\dfrac{\dfrac{1}{5}+\dfrac{3}{8}+\dfrac{5}{11}}{-\dfrac{3}{10}+\dfrac{9}{10}-\dfrac{15}{22}}=2016+\dfrac{453}{440}:\dfrac{-9}{110}\)
\(=2016-\dfrac{151}{12}=\dfrac{24343}{12}\)
b: \(=\dfrac{1,3-13.2}{2.6}-\dfrac{5}{6}:2\)
\(=\dfrac{-119}{26}-\dfrac{5}{12}=\dfrac{-779}{156}\)
c: \(=15\left(-1-\dfrac{5}{7}-\dfrac{2}{7}\right)+\left(-105\right)\cdot\dfrac{1}{105}\)
\(=-30-1=-31\)
23 tháng 9 2016
\(\left(\frac{1}{2}\right)^5\times x=\left(\frac{1}{2}\right)^7\)
\(x=\left(\frac{1}{2}\right)^7\div\left(\frac{1}{2}\right)^5\)
\(x=\left(\frac{1}{2}\right)^{7-5}=\left(\frac{1}{2}\right)^2=\frac{1}{4}\) .
\(\left(\frac{3}{7}\right)^2\times x=\left(\frac{9}{21}\right)^2\)
\(\left(\frac{3}{7}\right)^2\times x=\left(\frac{3}{7}\right)^4\)
\(x=\left(\frac{3}{7}\right)^4\div\left(\frac{3}{7}\right)^2\)
\(x=\left(\frac{3}{7}\right)^{4-2}=\left(\frac{3}{7}\right)^2=\frac{9}{49}\)
\(2^x=2\Rightarrow x=1\)
\(3^x=3^4\Rightarrow x=4\)
\(7^x=7^7\Rightarrow x=7\)
\(\left(-3\right)^x=\left(-3\right)^5\Rightarrow x=5\)
\(\left(-5\right)^x=\left(-5\right)^4\Rightarrow x=4\)
\(2^x=4\Leftrightarrow2^x=2^2\Rightarrow x=2\)
\(2^x=8\Leftrightarrow2^x=2^3\Rightarrow x=3\)
\(2^x=16\Leftrightarrow2^x=2^4\Rightarrow x=4\)
\(3^{x+1}=3^2\Leftrightarrow x+1=2\Leftrightarrow x=2-1\Rightarrow x=1\)
\(5^{x-1}=5\Leftrightarrow x-1=1\Leftrightarrow x=1+1\Rightarrow x=2\)
\(6^{x+4}=6^{10}\Leftrightarrow x+4=10\Leftrightarrow x=10-4\Rightarrow x=6\)
\(5^{2x-7}=5^{11}\Leftrightarrow2x-7=11\Leftrightarrow2x=11+7\Leftrightarrow2x=18\Leftrightarrow x=18\div2\Rightarrow x=9\)
\(\left(-2\right)^{4x+2}=64\)
\(2^{-4x+2}=2^6\Leftrightarrow-4x+2=6\Leftrightarrow-4x=6-2\Leftrightarrow-4x=4\Leftrightarrow x=4\div\left(-4\right)\Rightarrow x=-1\)
\(\left(\frac{1}{2}\right)^x=\left(\frac{1}{2}\right)^5\Rightarrow x=5\)
\(\left(\frac{5}{6}\right)^{2x}=\left(\frac{5}{6}\right)^5\Rightarrow2x=5\Rightarrow x=\frac{5}{2}\)
\(\left(\frac{3}{4}\right)^{2x-1}=\left(\frac{3}{4}\right)^{5x-4}\Rightarrow2x-1=5x-4\)
\(2x-5x=-4+1\)
\(-3x=-3\Rightarrow x=1\)
\(\left(\frac{-1}{10}\right)^x=\frac{1}{100}\)
\(\left(\frac{1}{10}\right)^{-x}=\left(\frac{1}{10}\right)^2\Rightarrow-x=2\Rightarrow x=-2\)
\(\left(\frac{-3}{2}\right)^x=\frac{9}{4}\)
\(\left(\frac{3}{2}\right)^{-x}=\left(\frac{3}{2}\right)^2\Rightarrow-x=2\Rightarrow x=-2\)
\(\left(\frac{-3}{5}\right)^{2x}=\frac{9}{25}\)
\(\left(\frac{3}{5}\right)^{-2x}=\left(\frac{3}{5}\right)^2\Rightarrow-2x=2\Rightarrow x=-1\)
\(\left(\frac{-2}{3}\right)^x=\frac{-8}{27}\)
\(\left(\frac{-2}{3}\right)^x=\left(\frac{-2}{3}\right)^3\Rightarrow x=3\).
hehe.
đánh tới què tay, hoa mắt lun r nekkk!!
29 tháng 11 2016
a)\(\left(-3\right)^{x+3}=-\frac{1}{27}\)
\(\left(-3\right)^{x+3}=\left(-\frac{1}{3}\right)^3\)
\(\left(-3\right)^{x+3}=\left(-\frac{3^0}{3^1}\right)^3\)
\(\left(-3\right)^{x+3}=\left(-3^{-1}\right)^3\)
\(\left(-3\right)^{x+3}=\left(-3\right)^{-3}\)
\(\Rightarrow x+3=-3\)
\(\Rightarrow x=-6\)
b)\(\left(-6\right)^{2x+2}=\frac{1}{36}\)
\(\left(-6\right)^{2x+2}=\left(-\frac{1}{6}\right)^2\)
\(\left(-6\right)^{2x+2}=\left(-\frac{6^0}{6^1}\right)^2\)
\(\left(-6\right)^{2x+2}=\left(-6^{-1}\right)^2\)
\(\left(-6\right)^{2x+2}=\left(-6\right)^{-2}\)
\(\Rightarrow2x+2=-2\)
\(\Rightarrow2x=-4\)
\(\Rightarrow x=-2\)
c)\(\left(-3\right)^{x+5}=\frac{1}{81}\)
\(\left(-3\right)^{x+5}=\left(-\frac{1}{3}\right)^4\)
\(\left(-3\right)^{x+5}=\left(-\frac{3^0}{3^1}\right)^4\)
\(\left(-3\right)^{x+5}=\left(-3^{-1}\right)^4\)
\(\left(-3\right)^{x+5}=\left(-3\right)^{-4}\)
\(\Rightarrow x+5=-4\)
\(\Rightarrow x=-9\)
29 tháng 11 2016
d)\(\left(\frac{1}{9}\right)^x=\left(\frac{1}{27}\right)^6\)
\(\left[\left(\frac{1}{3}\right)^2\right]^x=\left[\left(\frac{1}{3}\right)^3\right]^6\)
\(\left(\frac{1}{3}\right)^{2x}=\left(\frac{1}{3}\right)^{18}\)
\(\Rightarrow2x=18\)
\(\Rightarrow x=9\)
e)\(\left(\frac{4}{9}\right)^x=\left(\frac{8}{27}\right)^6\)
\(\left[\left(\frac{2}{3}\right)^2\right]^x=\left[\left(\frac{2}{3}\right)^3\right]^6\)
\(\left(\frac{2}{3}\right)^{2x}=\left(\frac{2}{3}\right)^{18}\)
\(\Rightarrow2x=18\)
\(\Rightarrow x=9\)
6 tháng 9 2017
\(A=\left(-\frac{5}{11}\right).\frac{7}{15}+\frac{11}{-5}.\frac{30}{33}\)
\(A=-\frac{7}{33}+-2\)
\(A=-\frac{73}{33}\)
[ A] = -2
MM
22 tháng 8 2019
1,\(\frac{2}{9}.\left(x-\frac{9}{4}\right)+\frac{1}{2}=\frac{3}{7}.\left(7-\frac{1}{6}\right)+\frac{1}{3}\)
\(\frac{2}{9}.\left(x-\frac{9}{4}\right)+\frac{1}{2}=\frac{3}{7}.\frac{41}{6}+\frac{1}{3}\)
\(\frac{2}{9}.\left(x-\frac{9}{4}\right)+\frac{1}{2}=\frac{41}{14}+\frac{1}{3}\)
\(\frac{2}{9}.\left(x-\frac{9}{4}\right)+\frac{1}{2}=\frac{137}{42}\)
\(\frac{2}{9}.\left(x-\frac{9}{4}\right)=\frac{137}{42}-\frac{1}{2}\)
\(\frac{2}{9}.\left(x-\frac{9}{4}\right)=\frac{58}{21}\)
\(\left(x-\frac{9}{4}\right)=\frac{5}{2}:\frac{2}{9}\)
\(\left(x-\frac{9}{4}\right)=\frac{45}{4}\)
\(x=\frac{45}{4}+\frac{9}{4}\)
\(x=\frac{27}{2}\)
31 tháng 10 2018
Ôi trời nhiều thía ? làm từng câu một ha !
a \(\hept{\begin{cases}\left(x+5\right)\left(y-2\right)=\left(x+2\right)\left(y-1\right)\\\left(x-4\right)\left(y+7\right)=\left(x-3\right)\left(y+4\right)\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}xy-2x+5y-10=xy-x+2y-2\\xy+7x-4y-28=xy+4x-3y-12\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}-x+3y=8\\3x-y=16\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}-3x+9y=24\\3x-y=16\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}-3x+9y=24\\3x-y-3x+9y=16+24\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}-3x+9y=24\\8y=40\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x=7\\y=5\end{cases}}\)
31 tháng 10 2018
b, ĐKXĐ \(x\ne\pm y\)
Đặt \(\frac{1}{x+y}=a\) và \(\frac{1}{x-y}=b\)(a và b khác 0)
Ta có hệ \(\hept{\begin{cases}a-2b=2\\5a-4b=3\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}2a-4b=4\\5a-4b=3\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}2a-4b=4\\5a-4b-2a+4b=3-4\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}2a-4b=4\\3a=-1\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}a=-\frac{1}{3}\\b=-\frac{7}{6}\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}\frac{1}{x+y}=-\frac{1}{3}\\\frac{1}{x-y}=-\frac{7}{6}\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x+y=-3\\x-y=-\frac{6}{7}\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x+y-x+y=-3+\frac{6}{7}\\x-y=-\frac{6}{7}\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}2y=-\frac{15}{7}\\x-y=-\frac{6}{7}\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}x=-\frac{27}{14}\\y=-\frac{15}{14}\end{cases}}\)
2x-\(\frac{1}{3}\)=1-\(\frac{5}{6}\)
2x-\(\frac{1}{3}\)=\(\frac{1}{6}\)
2x=\(\frac{1}{6}\)+\(\frac{1}{3}\)
2x=1/6 +2/6
2x=\(\frac{1}{2}\)
x=1/2 : 2
x/\(\frac{1}{4}\)
\(\frac{7}{9}\):(2+\(\frac{3}{4}\)x)+\(\frac{5}{9}\)=\(\frac{23}{27}\)
7/9 :(2+3/4x)=\(\frac{23}{27}\)-\(\frac{5}{9}\)
7/9 :(2+3/4x)=\(\frac{23}{27}\)-\(\frac{15}{27}\)
7/9 :(2+3/4x)=\(\frac{8}{27}\)
(2+3/4x) =\(\frac{7}{9}\) . \(\frac{27}{8}\)
(2+3/4x) =\(\frac{21}{8}\)
\(\frac{3}{4}\)x =\(\frac{21}{8}\)-2
3/4x =21/8 -16/8
3/4x = 5/8
x =\(\frac{5}{8}\) : \(\frac{3}{4}\)
x =5/8 . 4/3
x =\(\frac{20}{24}\)