\(=\left(\dfrac{11}{10}+\dfrac{7}{10}+\dfrac{1}{10}\right)+\left(\dfrac{17}{20}+\dfrac{9}{20}+\dfrac{3}{20}\right)\\ =\dfrac{19}{10}+\dfrac{29}{20}=\dfrac{19\times2}{10\times2}+\dfrac{29}{20}=\dfrac{38}{20}+\dfrac{29}{20}\\ =\dfrac{47}{20}\)

\(H=\left(\dfrac{11}{10}+\dfrac{7}{10}+\dfrac{1}{10}\right)+\left(\dfrac{17}{20}+\dfrac{9}{20}+\dfrac{3}{20}\right)\)

\(H=\dfrac{19}{10}+\dfrac{29}{20}\)

\(H=\dfrac{67}{20}\)

\(H=\dfrac{11}{10}+\dfrac{17}{20}+\dfrac{7}{10}+\dfrac{9}{20}+\dfrac{1}{10}+\dfrac{3}{20}\\ \Rightarrow H=\left(\dfrac{11}{10}+\dfrac{7}{10}+\dfrac{1}{10}\right)+\left(\dfrac{17}{20}+\dfrac{9}{20}+\dfrac{3}{20}\right)\\ \Rightarrow H=\dfrac{19}{10}+\dfrac{29}{20}\\ \Rightarrow H=\dfrac{38}{20}+\dfrac{29}{20}\\ \Rightarrow H=\dfrac{67}{20}\)

Ta có: \(\dfrac{x}{y}=\dfrac{3}{2}\)

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

Đặt \(\dfrac{x}{3}=\dfrac{y}{2}=k\)

\(\Leftrightarrow\left\{{}\begin{matrix}x=3k\\y=2k\end{matrix}\right.\)

Ta có: \(H=\dfrac{2x-3y}{x-5y}\)

\(=\dfrac{2\cdot3k-3\cdot2k}{3k-5\cdot2k}=\dfrac{6k-6k}{3k-10k}=0\)

Ta có: ⇔x3=y2⇔x3=y2

Đặt H=2x−3yx−5yH=2x−3yx−5y

Toán lớp 1 khó thế à 

a) 25.2³ − 3² + 125 = 25.8 – 9 + 125 = 316.

b) 2.3² + 5.(2 + 3) = 2.9+5.5 = 43.

=2700

=> 2700

a/3125