\(15\dfrac{1}{4}:\dfrac{5}{7}-25\dfrac{1}{4}:\dfrac{5}{7}=\dfrac{61}{4}:\dfrac{5}{7}-\dfrac{101}{4}:\dfrac{5}{7}\)

\(=\dfrac{61}{4}.\dfrac{7}{5}-\dfrac{101}{4}.\dfrac{7}{5}=\left(\dfrac{61}{4}-\dfrac{101}{4}\right).\dfrac{7}{5}=-10.\dfrac{7}{5}=-14\)

\(9.\left(-\dfrac{1}{3}\right)^2+\dfrac{1}{6}.\sqrt{4}=9.\dfrac{1}{9}+\dfrac{1}{6}.2\)

\(=1+\dfrac{1}{3}=\dfrac{3}{3}+\dfrac{1}{3}=\dfrac{4}{3}\)

\(\left(\dfrac{1}{5}-\dfrac{3}{2}.x\right)^2=\dfrac{9}{4}\)

\(\Leftrightarrow\left[{}\begin{matrix}\left(\dfrac{1}{5}-\dfrac{3}{2}.x\right)^2=\left(\dfrac{3}{2}\right)^2\\\left(\dfrac{1}{5}-\dfrac{3}{2}.x\right)^2=\left(-\dfrac{3}{2}\right)^2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{5}-\dfrac{3}{2}.x=\dfrac{3}{2}\\\dfrac{1}{5}-\dfrac{3}{2}.x=-\dfrac{3}{2}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{3}{2}.x=\dfrac{1}{5}-\dfrac{3}{2}\\\dfrac{3}{2}.x=\dfrac{1}{5}-\left(-\dfrac{3}{2}\right)\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}\dfrac{3}{2}.x=-\dfrac{13}{10}\\\dfrac{3}{2}.x=\dfrac{17}{10}\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{13}{10}:\dfrac{3}{2}\\x=\dfrac{17}{10}:\dfrac{3}{2}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{13}{15}\\x=\dfrac{17}{15}\end{matrix}\right.\)

 Vậy ................

@Lê Thanh Huyền

Ủa chứ cậu nghĩ tự nhiên mình đi nói ngkhac không có= chứng?

Cậu ơi cop ít thôi nhé.

4 kg dâu gấp 8 kg dâu số lần là:

  4:8=0,5(lần)

Ngâm 4kg dâu cần số kg đường là:

 2.0,5=1(kg)

         Đ/s:............

Củm ơn bạn đã mở đg cho con bé ngu si hết thuốc chữa này :))

Cùng trg :v