\(=25x^2-9\)

25x²-9

\(=25x^2-9\)

\(\dfrac{-1}{39}+\dfrac{-1}{52}=\dfrac{-7}{156}\)

\(\dfrac{-6}{9}+\dfrac{-12}{16}=\dfrac{-17}{12}\)

\(\dfrac{-2}{5}-\dfrac{-3}{11}=\dfrac{-7}{55}\)

\(\dfrac{-34}{37}.\dfrac{74}{-85}=\dfrac{4}{5}\)

\(\dfrac{-5}{9}:\dfrac{-7}{18}=\dfrac{10}{7}\)

Chúc bạn học tốt!!!

a) \(\left(-\dfrac{1}{39}\right)+\left(-\dfrac{1}{52}\right)=\dfrac{-4-3}{156}=-\dfrac{7}{156}\)

b) \(\left(-\dfrac{6}{9}\right)+\left(-\dfrac{12}{16}\right)=-\dfrac{6}{9}-\dfrac{12}{16}=-\dfrac{17}{12}\)

c) \(-\dfrac{2}{5}-\left(-\dfrac{3}{11}\right)=-\dfrac{2}{5}+\dfrac{3}{11}=-\dfrac{7}{55}\)

d) \(\left(-\dfrac{34}{37}\right)\cdot\left(-\dfrac{74}{85}\right)=2\cdot\dfrac{2}{5}=\dfrac{4}{5}\)

e) \(\left(-\dfrac{5}{9}\right):\left(-\dfrac{7}{18}\right)=\dfrac{5}{9}\cdot\dfrac{18}{7}=5\cdot\dfrac{2}{7}=\dfrac{10}{7}\)

\(\dfrac{1}{\sqrt[3]{4}+\sqrt[3]{2}+1}=\dfrac{\sqrt[3]{2}-1}{\left(\sqrt[3]{2}-1\right)\left(\sqrt[3]{4}+\sqrt[3]{2}+1\right)}\)

\(=\dfrac{\sqrt[3]{2}-1}{2-1}=\sqrt[3]{2}-1\)

bài nào hả bn ?
 

2x - 2x +6 = 64 

TỰ LÀM

\(\frac{3}{10}\left(-\frac{5}{3}+\frac{3}{5}\right)+\left(-\frac{3}{10}\right)\left(\frac{3}{9}+\left(-\frac{2}{5}\right)\right)=\frac{3}{10}\left(-\frac{5}{3}+\frac{3}{5}-\frac{3}{9}+\frac{2}{5}\right)\)

\(=\frac{3}{10}\left(-\frac{18}{9}+\frac{5}{5}\right)\)

\(=\frac{3}{10}\left(-2+1\right)\)

\(=\frac{3}{10}.\left(-1\right)\)

\(=-\frac{3}{10}\)