\(b,\dfrac{1}{5}:x=\dfrac{1}{5}-\dfrac{1}{7}\)

\(\dfrac{1}{5}:x=\dfrac{7}{35}-\dfrac{5}{35}\)

\(\dfrac{1}{5}:x=\dfrac{2}{35}\)

\(x=\dfrac{1}{5}:\dfrac{2}{35}\)

\(x=\dfrac{1}{5}.\dfrac{35}{2}\)

\(x=\dfrac{7}{2}\)

\(x-\left(\dfrac{50x}{100}+\dfrac{25x}{100}\right)=11\dfrac{1}{4}\)

\(x-\dfrac{3x}{4}=\dfrac{45}{4}\)

\(\dfrac{x}{4}=\dfrac{45}{4}\Rightarrow x=45\)

Đầu bài là :

x -\(\left(\dfrac{50x}{100}+\dfrac{25x}{200}\right)\)= 11\(\dfrac{1}{4}\)

mà bn

<=>\(x+x-\frac{25x}{100}-\frac{25}{100}=60\)

<=>\(2x-\frac{50x}{100}=60\)

<=>\(\frac{150x}{100}=60\)

<=> 150x=6000

<=> x=40

 \(x-\left(\frac{50x}{100}+\frac{25x}{100}\right)=\frac{45}{4}\)

      \(x-\left(\frac{50x+25x}{100}\right)=\frac{45}{4}\)

                    \(x-\frac{75x}{100}=\frac{45}{4}\)

               \(x-x\times\frac{3}{4}=\frac{45}{4}\)

         \(x\times\left(1-\frac{3}{4}\right)=\frac{45}{4}\)

                       \(x\times\frac{1}{4}=\frac{45}{4}\)

                                 \(x=\frac{45}{4}\div\frac{1}{4}\)

                                 \(x=45\)

\(x-\left(\frac{50x}{100}+\frac{25x}{200}\right)=\frac{45}{4}\)

\(x-\left(\frac{100x}{200}+\frac{25x}{200}\right)=\frac{45}{4}\)

\(x-\left(\frac{100x+25x}{200}\right)=\frac{45}{4}\)

\(x-\frac{125x}{200}=\frac{45}{4}\)

\(x-x\frac{5}{8}=\frac{45}{4}\)

\(x\left(1-\frac{5}{8}\right)=\frac{45}{4}\)

\(x.\frac{3}{8}=\frac{45}{4}\)

\(x\)=\(\frac{45}{4}:\frac{3}{8}\)

\(x\)=\(30\)

ko biết

Cố đợi sang năm nhe

a) \(2^{x+2}-2^2=96\)

 <=> \(2^x.2^2-2^x=96\)

 <=> \(2^x\left(4-1\right)=96\)

<=> \(3.2^x=96\)

<=> \(2^x=32\)

<=> \(2^x=2^5\)

<=> x = 5 

b, \(x-\left(\frac{50x}{100}+\frac{25x}{200}\right)=11\frac{1}{4}\)

\(\Rightarrow x-\left(\frac{1x}{2}+\frac{1x}{8}\right)=\frac{45}{4}\)

\(\Rightarrow x-\left(\frac{4x}{8}+\frac{1x}{8}\right)=\frac{45}{4}\)

\(\Rightarrow x-\frac{5x}{8}=\frac{45}{4}\)

\(\Rightarrow\frac{8x}{8}-\frac{5x}{8}=\frac{45}{4}\)

\(\Rightarrow\frac{3x}{8}=\frac{45}{4}\Rightarrow x=\frac{45}{4}\div\frac{3}{8}=30\)

Vậy x = 30 

uk

a)x=30

b)x=65

bn giải cụ thể hơn đi , mình ko hiểu