Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
\(\dfrac{2x-1}{3}=\dfrac{7}{27\left(2x+1\right)}\)
\(\Leftrightarrow27\left(4x^2-1\right)=21\)
\(\Leftrightarrow4x^2-1=\dfrac{7}{9}\)
\(\Leftrightarrow4x^2=\dfrac{16}{9}\)
\(\Leftrightarrow x^2=\dfrac{4}{9}\)
=>x=2/3 hoặc x=-2/3
\(3,8:\left(2x\right)=\frac{1}{4}:2\frac{2}{3}\)
\(3,8:\left(2x\right)=\frac{3}{32}\)
\(\Rightarrow2x=3,8:\frac{3}{32}\)
\(\Rightarrow x=\frac{608}{15}:2=\frac{304}{15}\)
\(\left(a\right)\) tức là bài a hay là gt trog tỉ lệ thức v pn?
a, 0,4 : x = x : 0,9
<=> x2 = 0,4 . 0,9
<=> x2 = 0,36
<=> x = 0,6 hoặc -0,6
b, \(13\frac{1}{3}\div1\frac{1}{3}=26\div\left(2x-1\right)\)
\(\Leftrightarrow\frac{40}{3}\div\frac{4}{3}=26\div\left(2x-1\right)\)
\(\Leftrightarrow10=26\div\left(2x-1\right)\)
\(\Leftrightarrow2x-1=\frac{13}{5}\)
\(\Leftrightarrow2x=\frac{18}{5}\)
\(\Leftrightarrow x=\frac{9}{5}\)
c, \(0,2\div1\frac{1}{5}=\frac{2}{3}\div\left(6x+7\right)\)
\(\Leftrightarrow\frac{1}{5}\div\frac{6}{5}=\frac{2}{3}\div\left(6x+7\right)\)
\(\Leftrightarrow\frac{1}{6}=\frac{2}{3}\div\left(6x+7\right)\)
\(\Leftrightarrow6x+7=4\)
\(\Leftrightarrow6x=-3\)
\(\Leftrightarrow x=\frac{-1}{2}\)
d, \(\frac{37-x}{x+13}=\frac{3}{7}\)
\(\Leftrightarrow7\left(37-x\right)=3\left(x+13\right)\)
\(\Leftrightarrow259-7x=3x+39\)
\(\Leftrightarrow-10x=-220\)
\(\Leftrightarrow x=22\)
\(\Leftrightarrow-\dfrac{8}{17}\left(\dfrac{5}{2}-3x\right)=\dfrac{5}{3}\left(2x+\dfrac{8}{5}\right)\)
\(\Leftrightarrow x\cdot\dfrac{24}{17}-\dfrac{20}{17}=\dfrac{10}{3}x+\dfrac{8}{3}\)
\(\Leftrightarrow x\cdot\dfrac{-98}{51}=\dfrac{196}{51}\)
hay x=-2
a) Lm r nkoa!
b) \(\left(0,25x\right):3=\frac{5}{6}:0,125\)
\(=\left(0,25x\right):3=\frac{20}{3}\)
\(\Rightarrow0,25x=\frac{20}{3}\cdot3=20\)
\(\Rightarrow x=20:0,25=80\)
\(\Rightarrow x=80\)
c) \(0,01:2,5=\left(0,75x\right):0,75\)
\(=\frac{1}{250}=\left(0,75x\right):0,75\)
\(\Rightarrow0,75x=\frac{1}{250}\cdot0,75=\frac{3}{1000}\)
\(\Rightarrow x=\frac{3}{1000}:0,75=\frac{1}{250}\)
\(\Rightarrow x=\frac{1}{250}\)
d) \(1\frac{1}{3}:0,8=\frac{2}{3}:\left(0,1x\right)\)
\(=\frac{5}{3}=\frac{2}{3}:\left(0,1x\right)\)
\(\Rightarrow0,1x=\frac{2}{3}:\frac{5}{3}=\frac{2}{5}\)
\(\Rightarrow x=\frac{2}{5}:0,1=4\)
\(\Rightarrow4\)
X=-6 hoặc x = 4/6