\(\left(-\dfrac{1}{6}\right)\cdot\dfrac{19}{4}\)
\(=-\dfrac{19}{24}\)

-1/6 . 19/4

=-2/12 . 57/12

=-114/12 = -19/2

chúc bạn học tốt
 

Ta có:
\(\left(\dfrac{3}{5}\right)^2< 1\)

\(1< \left(\dfrac{5}{3}\right)^2\)
Do đó \(\left(\dfrac{3}{5}\right)^2< \left(\dfrac{5}{3}\right)^2\)

a/\(-\dfrac{1}{6}+\left(-\dfrac{5}{8}+\dfrac{7}{6}\right)\)
\(=\left(-\dfrac{1}{6}+\dfrac{7}{6}\right)-\dfrac{5}{8}\)
\(=1-\dfrac{5}{8}\)
\(=\dfrac{8}{8}-\dfrac{5}{8}=\dfrac{3}{8}\)
b/\(\left(\dfrac{2}{5}\right)^2+5\dfrac{1}{2}\cdot\left(4,5-2\right)+\dfrac{2^3}{\left(-4\right)}\)
\(=\dfrac{4}{25}+\dfrac{11}{2}\cdot\dfrac{5}{2}+-\dfrac{2^3}{2^2}\)
\(=\dfrac{4}{25}+\dfrac{55}{4}+\left(-2\right)\)
\(=\dfrac{16}{100}+\dfrac{1375}{100}-\dfrac{200}{100}\)
\(=\dfrac{1191}{100}=11,91\)

bằng 239/ 210 nha

\(\left(-\dfrac{1}{15}\right)-\dfrac{15}{14}\)
\(=-\dfrac{14}{210}-\dfrac{225}{210}\)
\(=-\dfrac{239}{210}\)

Dũng được Tuấn cho số bi là: 21 x \(\dfrac{3}{7}\) = 9 ( viên bi)

Tuấn còn lại số bi là: 21 - 9 = 12 ( viên bi)

Kết luận:.........

A = 2022²⁰²²

A = (2022⁴)⁵⁰⁵.2022² 

A = \(\overline{...6}\)⁵⁰⁵. \(\overline{...4}\)

A = \(\overline{...4}\)