Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
c: Ta có: \(\dfrac{2}{5}\cdot\left[\left(\dfrac{3}{5}\right)^2:\left(-\dfrac{1}{5}\right)^2-7\right]\cdot\left(1000\right)^0\cdot\left|-\dfrac{11}{15}\right|\)
\(=\dfrac{2}{5}\cdot\left(\dfrac{9}{25}:\dfrac{1}{25}-7\right)\cdot1\cdot\dfrac{11}{15}\)
\(=\dfrac{2}{5}\cdot\dfrac{11}{15}\cdot2\)
\(=\dfrac{44}{75}\)
#)Giải :
\(\left(x+2\right)^{n+1}=\left(x+2\right)^{n+11}\)
\(\Rightarrow\left(x+2\right)^{n+1}-\left(x+2\right)^{n+11}=0\)
\(\Rightarrow\left(x+2\right)^{n+1}.\left[1-\left(x+2\right)^{10}\right]=0\)
\(\Rightarrow\left(x+2\right)^{n+1}=0\)hoặc \(1-\left(x+2\right)^{10}=0\)
Với \(1-\left(x+2\right)^{10}=0\Rightarrow x+2=0\Rightarrow x=-2\)
Với \(1-\left(x+2\right)^{n+1}=0\Rightarrow\left(x+2\right)^{10}=1\Rightarrow\orbr{\begin{cases}x+2=1\\x+2=-1\end{cases}\Rightarrow\orbr{\begin{cases}x=-1\\x=-3\end{cases}}}\)
\(2x-\frac{5}{9}=\frac{1}{3}+\text{ }[\frac{11}{3}-4+\frac{2}{3}]\)
\(2x-\frac{5}{9}=\frac{1}{3}+\text{ }[-\frac{1}{3}+\frac{2}{3}]\)
\(2x-\frac{5}{9}=\frac{1}{3}+\frac{1}{3}\)
\(2x-\frac{5}{9}=\frac{2}{3}\)
\(2x=\frac{11}{9}\)
\(x=\frac{11}{18}\)
Vậy \(x=\frac{11}{18}\)
\(\frac{x+1}{2009}+\frac{x+2}{2008}+\frac{x+3}{2007}=\frac{x+10}{2000}+\frac{x+11}{1999}+\frac{x+12}{1998}.\)
\(\frac{x+1}{2009}+1+\frac{x+2}{2008}+1+\frac{x+3}{2007}+1=\frac{x+10}{2000}+1+\frac{x+11}{1999}+1+\frac{x+12}{1998}+1.\)(cộng 2 vế cho 3)
\(\frac{x+1}{2009}+\frac{2009}{2009}+\frac{x+2}{2008}+\frac{2008}{2008}+\frac{x+3}{2007}+\frac{2007}{2007}=\frac{x+10}{2000}+\frac{2000}{2000}+\frac{x+11}{1999}+\frac{1999}{1999}+\frac{x+12}{1998}+\frac{1998}{1998}.\)
\(\frac{x+2010}{2009}+\frac{x+2010}{2008}+\frac{x+2010}{2007}=\frac{x+2010}{2000}+\frac{x+2010}{1999}+\frac{x+2010}{1998}.\)
\(\frac{x+2010}{2009}+\frac{x+2010}{2008}+\frac{x+2010}{2007}-\frac{x+2010}{2000}-\frac{x+2010}{1999}-\frac{x+2010}{1998}=0\)
x+2010=0
x=-2010
\(\frac{x+1}{2009}+\frac{x+2}{2008}+\frac{x+3}{2007}=\frac{x+10}{2000}+\frac{x+11}{1999}+\frac{x+12}{1998}\)
\(\Leftrightarrow\left(1+\frac{x+1}{2009}\right)+\left(1+\frac{x+2}{2008}\right)+\left(1+\frac{x+3}{2007}\right)\)
\(=\left(1+\frac{x+10}{2000}\right)+\left(1+\frac{x+11}{1999}\right)+\left(1+\frac{x+12}{1998}\right)\)
\(\Leftrightarrow\frac{x+2010}{2009}+\frac{x+2010}{2008}+\frac{x+2010}{2007}=\frac{x+2010}{2000}+\frac{x+2010}{1999}+\frac{x=2010}{1998}\)
\(\Leftrightarrow\frac{x+2010}{2009}+\frac{x+2010}{2008}+\frac{x+2010}{2007}-\frac{x+2010}{2000}-\frac{x+2010}{1999}-\frac{x+2010}{1998}\)
\(=0\)
\(\Leftrightarrow\left(x+2010\right)\left(\frac{1}{2009}+\frac{1}{2008}+\frac{1}{2007}-\frac{1}{2000}-\frac{1}{1999}-\frac{1}{1998}\right)=0\)
\(\Leftrightarrow x+2010=0\)
\(\Leftrightarrow x=-2010\)
\(\left(1+\dfrac{2}{3}\right).\left(1+\dfrac{2}{4}\right).\left(1+\dfrac{2}{5}\right)....\left(1+\dfrac{2}{2020}\right).\left(1+\dfrac{2}{2021}\right)\)
= \(\dfrac{5}{3}.\dfrac{6}{4}.\dfrac{7}{5}.\dfrac{8}{6}.\dfrac{9}{7}....\dfrac{2022}{2020}.\dfrac{2023}{2021}\)
= \(\dfrac{1}{3}.\dfrac{1}{4}.2022.2023\)
= \(\dfrac{337.2023}{2}\)
= \(\dfrac{\text{681751}}{2}\)
\(\left(x-\frac{7}{3}\right):2\frac{3}{21}+\frac{3}{5}=0,16\)
<=> \(\left(x-\frac{7}{3}\right):\frac{45}{21}+\frac{3}{5}=\frac{4}{25}\)
<=> \(\left(x-\frac{7}{3}\right):\frac{15}{7}=-\frac{11}{25}\)
<=> \(x-\frac{7}{3}=\frac{-33}{35}\)
<=> \(x=\frac{146}{105}\)
\(\left(x+\frac{5}{6}\right).2\frac{2}{5}-1\frac{1}{4}=0,35\)
<=> \(\left(x+\frac{5}{6}\right).\frac{12}{5}-\frac{5}{4}=\frac{7}{20}\)
<=> \(\left(x+\frac{5}{6}\right).\frac{12}{7}=\frac{8}{5}\)
<=> \(x+\frac{5}{6}=\frac{14}{15}\)
<=> \(x=\frac{1}{10}\)
học tốt
\(\dfrac{11}{5}-\left(0,35+x\right)=1\dfrac{1}{2}\\ \dfrac{11}{5}-\left(\dfrac{7}{20}+x\right)=\dfrac{3}{2}\\ \dfrac{11}{5}-\dfrac{7}{20}-x=\dfrac{3}{2}\\ \dfrac{44}{20}-\dfrac{7}{20}-x=\dfrac{3}{2}\\ \dfrac{37}{20}-x=\dfrac{3}{2}\\ x=\dfrac{37}{20}-\dfrac{3}{2}\\ x=\dfrac{7}{20}\)