Biết $\frac{1+2x}{3x-1}$ thế nào hả bạn?

Tìm số tự nhiên x:  \(2^{x-1}+5.2^{x-2}=224\Leftrightarrow2.2^{x-2}+5.2^{x-2}=224\)

\(\Leftrightarrow2^{x-2}.\left(5+2\right)=224\Leftrightarrow2^{x-2}.7=224\)

\(\Rightarrow2^{x-2}=32\Leftrightarrow2^{x-2}=2^5\)\(\Rightarrow x-2=5\Leftrightarrow x=7\)

Vậy x=7

Tìm x biết: \(\frac{3}{7}=\frac{2x+1}{3x+5}\)

\(\Rightarrow3\left(3x+5\right)=7\left(2x+1\right)\Leftrightarrow9x+15=14x+7\)

\(\Leftrightarrow14x+7-\left(9x+15\right)=0\Rightarrow5x+\left(-8\right)=0\)

\(\Leftrightarrow5x=8\Rightarrow x=\frac{8}{5}\)

Vậy x=8/5

phân số thỏa mãn là 35/8 nhé bạn

\(\dfrac{2x-3}{5}=\dfrac{x-2}{4}\)
\(\Rightarrow\left(2x-3\right)\cdot4=\left(x-2\right)\cdot5\)
\(\Rightarrow8x-12=5x-10\)
\(\Rightarrow8x-5x=-10+12\)
\(\Rightarrow3x=2\)
\(\Rightarrow x=\dfrac{2}{3}\)
Vậy \(x=\dfrac{2}{3}\)
#kễnh

\(\dfrac{2x-3}{5}=\dfrac{x-2}{4}\)

\(\Leftrightarrow4\left(2x-3\right)=5\left(x-2\right)\)

\(\Leftrightarrow8x-12=5x-10\)

\(\Leftrightarrow3x=2\)

\(\Leftrightarrow x=\dfrac{2}{3}\)

\(\frac{x}{4}=\frac{3}{2}\)

\(\Rightarrow\frac{x}{4}=\frac{6}{4}\)

\(\Rightarrow x=6\)

vậy_

b)\(\frac{2}{x}=\frac{x}{8}\)

\(\Rightarrow x^2=2\cdot8\)

\(x^2=16\Rightarrow x=4\)

c) \(\frac{x+3}{4}=\frac{5}{3}\)

\(3\left(x+3\right)=4\cdot5\)

\(3x+9=20\)

\(3x=11\)

\(x=\frac{11}{3}\)

Câu 1

a) <=> 3x-2=|2x+1|

<=> \(\left[\begin{array}{nghiempt}3x-2=2x+1\\2-3x=2x+1\end{array}\right.\)<=>\(\left[\begin{array}{nghiempt}x=3\\x=\frac{1}{5}\end{array}\right.\)

b)các phân só cần tìm a,b,c ta có a+b+c=213/70

và a:b:c=\(\frac{3}{5}:\frac{4}{1}:\frac{5}{2}\)=6:40:25

=> a= 9/35

b=12/7

c=15/14

Câu 2: => \(\frac{7.2x+x}{7}=\frac{1}{y}\)=> y(14x+1)=7

=> (x,y)=(0;7)