Toán Lớp 7: So sánh 2 phân số sau  a) -2021/ 2022 và – 2022/ 2023 b) -33/37 và -34 / 35

\[\begin{array}{l}
a)\frac{{ – 2021}}{{2022}} = \frac{{1 – 2022}}{{2022}} = \frac{1}{{2022}} – 1\\
\frac{{ – 2022}}{{2023}} = \frac{{1 – 2023}}{{2023}} = \frac{1}{{2023}} – 1\\
Do:\frac{1}{{2022}} > \frac{1}{{2023}}\\
= > \frac{1}{{2022}} – 1 > \frac{1}{{2023}} – 1\\
Vay:\frac{{ – 2021}}{{2022}} > \frac{{ – 2022}}{{2023}}\\
b)\frac{{ – 33}}{{37}} > \frac{{ – 34}}{{37}}\\
\frac{{ – 34}}{{35}} < \frac{{ – 34}}{{37}}\\
= > \frac{{ – 33}}{{37}} > \frac{{ – 34}}{{37}} > \frac{{ – 34}}{{35}}\\
vay:\frac{{ – 33}}{{37}} > \frac{{ – 34}}{{35}}
\end{array}\]