Tìm x
x x 3 = 1791
x : 3 = 27 083
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Bài 1:
Ta có: \(x-35\%\cdot x=\dfrac{1}{25}\)
\(\Leftrightarrow65\%\cdot x=\dfrac{1}{25}\)
\(\Leftrightarrow x=\dfrac{1}{25}:\dfrac{13}{20}=\dfrac{1}{25}\cdot\dfrac{20}{13}=\dfrac{4}{65}\)
Vậy: \(x=\dfrac{4}{65}\)
Bài 2:
a) Ta có: \(17\dfrac{2}{31}-\left(\dfrac{15}{17}+6\dfrac{2}{31}\right)\)
\(=17\dfrac{2}{31}-\dfrac{15}{17}-6\dfrac{2}{31}\)
\(=11+\dfrac{2}{31}-\dfrac{15}{17}\)
\(=\dfrac{5366}{527}\)
a)\(\Leftrightarrow\)\(x(27+30+43)=210500\)
\(\Leftrightarrow\)\(100x=210500\)
\(\Leftrightarrow\)\(x=2105\)
b)\(\Leftrightarrow\)\(x(128-12-16)=5208000\)
\(\Leftrightarrow\)\(100x=5208000\)
\(\Leftrightarrow\)\(x=52080\)
\(x\times27+x\times30+x\times43=210500\)
\(\Leftrightarrow x\times\left(27+30+43\right)=210500\)
\(\Leftrightarrow x\times100=210500\)
\(\Leftrightarrow x=2105\)
\(G=1+\frac{1}{3}+\frac{1}{9}+\frac{1}{27}+\frac{1}{81}+\frac{1}{243}\)
\(G=1+\frac{1}{3}+\frac{1}{3^2}+...+\frac{1}{3^5}\)
\(3G=3+1+\frac{1}{3}+...+\frac{1}{3^4}\)
\(3G-G=\left(3+1+...+\frac{1}{3^4}\right)-\left(1+\frac{1}{3}+...+\frac{1}{3^5}\right)\)
\(2G=3-\frac{1}{3^5}\)
\(2G=3-\frac{1}{243}\)
\(2G=\frac{729}{243}-\frac{1}{243}\)
\(G=\frac{728}{243}:2\)
\(G=\frac{364}{243}\)
\(\frac{3}{1.2}+\frac{3}{2.3}+...+\frac{3}{x.\left(x+1\right)}=\frac{6042}{2015}\)
\(3.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+...+\frac{1}{x}-\frac{1}{x+1}\right)=\frac{6042}{2015}\)
\(1-\frac{1}{x+1}=\frac{6042}{2015}:3\)
\(1-\frac{1}{x-1}=\frac{2014}{2015}\)
\(\frac{1}{x-1}=1-\frac{2014}{2015}\)
\(\frac{1}{x-1}=\frac{1}{2015}\)
\(\Rightarrow x-1=2015\)
\(\Rightarrow x=2016\)
`x^2 +3(x-1/2)=x^2+3`
`=>x^2+3x-3/2 =x^2+3`
`=> x^2 +3x-x^2=3+3/2`
`=> 3x=6/2+3/2`
`=>3x= 9/2`
`=>x= 9/2 : 3`
`=>x= 9/6= 3/2`
Vậy `x=3/2`
\(x-\dfrac{2}{3}.\left(x+9\right)=1\)
\(\Rightarrow x-\dfrac{2}{3}x-6=1\)
\(\Rightarrow\dfrac{1}{3}x=7\)
\(\Rightarrow x=21\)
x x 3 = 1791
x = 1791 : 3
x = 597
x : 3 = 27 083
x = 27083 x 3
x = 81249