\(6.\)

\(-5\in Z\)

\(\dfrac{-4}{3}\in Q\)

\(\dfrac{-2}{5}\in Q\)

\(N\subset Z\)

\(Z\subset Q\)

\(\dfrac{-3}{7}\notin Z\)

\(-2\notin N\)

\(1\dfrac{2}{5}\notin Z\)

\(8.\)

\(a.\dfrac{7}{8}\) và \(\dfrac{11}{2}\left(MSC=8\right)\)

Vì \(\dfrac{11}{2}=\dfrac{44}{8}\)

\(\Rightarrow\dfrac{7}{8}< \dfrac{44}{8}\) 

nên \(\dfrac{7}{8}< \dfrac{11}{2}\)

\(b.\dfrac{-2}{15}\) và \(\dfrac{3}{-20}\left(MSC=60\right)\)

Vì \(\dfrac{-2}{15}=\dfrac{-8}{60}\)

\(\dfrac{3}{-20}=\dfrac{-3}{20}=\dfrac{-9}{60}\)

\(\Rightarrow\dfrac{-8}{60}>\dfrac{-9}{60}\)

nên \(\dfrac{-2}{15}>\dfrac{3}{-20}\)

\(c.\dfrac{-17}{16}\) và \(\dfrac{-2}{3}\left(MSC=48\right)\)

Vì \(\dfrac{-17}{16}=\dfrac{-51}{48}\)

\(\dfrac{-2}{3}=\dfrac{-32}{48}\)

\(\Rightarrow\dfrac{-51}{48}< \dfrac{-32}{48}\)

nên\(\dfrac{-17}{16}< \dfrac{-2}{3}\)

\(d.\dfrac{-9}{21}\) và \(\dfrac{27}{-63}\left(MSC=63\right)\)

Vì \(\dfrac{-9}{21}=\dfrac{-27}{63}\)

\(\Rightarrow\dfrac{-27}{63}=\dfrac{-27}{63}\)

nên \(\dfrac{-9}{21}=\dfrac{27}{-63}\)

\(3.\)

\(n_{Mg}=\dfrac{m}{M}=\dfrac{24}{24}=1mol\)

PTHH: H₂S + Mg \(\rightarrow\) MgS + H₂

    TL:     1        1          1        1

   mol:      1 \(\leftarrow\) 1

\(m_{H_2S}=n.M=1.34=34g\)

\(C\%_{ddH_2S}=\dfrac{m_{H_2S}}{m_{ddH_2S}}.100\%=\dfrac{34}{200}.100\%=17\%\)

\(1.\)

tính \(m_{AgNO_3}\) của em đúng á chị thêm thui

PTHH: Cu + 2AgNO₃  \(\rightarrow\) Cu(NO₃)₂ + 2Ag

    TL:     1         2                    1               2

    mol: 0,04 \(\leftarrow\) 0,08

\(m_{Cu}=n.M=0,04.64=2,56g\)

\(2.\)

\(C\%_{ddBa\left(OH\right)_2}=\dfrac{m_{Ba\left(OH\right)_2}}{m_{ddBa\left(OH\right)_2}}.100\%\)

\(\Leftrightarrow m_{Ba\left(OH\right)_2}=\dfrac{m_{Ba\left(OH\right)_2}.C\%_{ddBa\left(OH\right)_2}}{100\%}\)

\(\Leftrightarrow m_{Ba\left(OH\right)_2}=\dfrac{50.12\%}{100\%}\)

\(\Rightarrow m_{Ba\left(OH\right)_2}=6g\)

\(n_{Ba\left(OH\right)_2}=\dfrac{m}{M}=\dfrac{6}{171}\approx0,04mol\)

PTHH: CO₂ + Ba(OH)₂ \(\rightarrow\) BaCO₃ + H₂O

    TL:      1            1                 1           1

    mol:    0,04  \(\leftarrow\)0,04

\(V_{CO_2}=n.22,4=0,04.22,4=0,896l\)

bài này chị làm sai rùi 

\(1.\)

\(C\%_{dd_{Cu}}=\dfrac{m_{Cu}}{m_{dd_{Cu}}}.100\%\)

\(\Leftrightarrow m_{Cu}=\dfrac{m_{ddCu}.C\%_{ddCu}}{100\%}\)

\(\Leftrightarrow m_{Cu}=\dfrac{170.8\%}{100\%}\)

\(\Rightarrow m_{Cu}=13,6g\)

1. My house is different from yours in that mine is small and old, while yours is large and modern.

2. This exercise isn't harder than I thought.

3. Life in the city is so much more exciting than life in the country, which is quiet.

4. Nga is shorter than Mai.

5. I am cleverer than Nga and Hoa.

\(-3\in Z\)

\(10\in N\)

\(-\dfrac{3}{7}\in Q\)

\(N\subset Z\)

em chưa ghi đề nhé

bài của chị bị sai nha :<

bài của chị bị sai nha :<