Bài 2: x=0; y=4

bn vào link này nha: https://hoc24.vn/hoi-dap/question/178472.html?pos=607686

\(a,\frac{3}{-5}=\frac{-3}{5};b,\frac{-13}{-7}=\frac{13}{7};c,\frac{-4}{8}=\frac{-1}{2};d,\frac{-34}{17}=\frac{-2}{1}\)

\(a,\frac{a}{-b}=\frac{-a}{b}vìa.b=-a.\left(-b\right)\)

\(b,\frac{-a}{-b}=\frac{a}{b}vì-a.b=-b.a\)

\(\frac{3}{-4}=\frac{-3}{4};\frac{-5}{-7}=\frac{5}{7};\frac{2}{-9}=\frac{-2}{9};\frac{-11}{-10}=\frac{11}{10}\)

\(\frac{5}{9}:\frac{-3}{22}+\frac{5}{9}:\frac{-3}{5}\)

=\(\frac{5}{9}.\frac{-22}{3}+\frac{5}{9}.\frac{-5}{3}\)

=\(\frac{5}{9}.\left(\frac{-22}{3}-\frac{5}{3}\right)\)

=\(\frac{5}{9}.\left(-9\right)\)

=-5

\(A,\left|-10-5\right|>\left|-10\right|-\left|5\right|\left(15>5\right)\)

\(B,\left|20-3\right|=\left|20\right|-\left|3\right|\left(=17\right)\)