\(3x^2-2x.\left(5+1,5x\right)+10\)

\(=3x^2-2x.5-2x.1,5x+10\)

\(=3x^2-3x^2-10x+10\)

\(=10-10x\)

\(=10.\left(1-x\right)\)

cam on ban nha

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

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

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

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

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

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

Phương trình trạng thái khí lí tưởng:

\(\dfrac{p_1\cdot V_1}{T_1}=\dfrac{p_2\cdot V_2}{T_2}\)

\(\Rightarrow\dfrac{4\cdot6}{293}=\dfrac{p_2\cdot4}{313}\)

\(\Rightarrow p_2=6,41atm\)

Chọn A

D

Chọn D