a: \(\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{-120\cdot11}{6}=-20\cdot11=-220\\y=\dfrac{-6\cdot33}{11}=-6\cdot3=-18\end{matrix}\right.\)
b \(\Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{-7\cdot27}{9}=-21\\y=\dfrac{-49\cdot9}{-7}=63\end{matrix}\right.\)
Tìm x, y ∈ Z:
a) \(\dfrac{4}{x}\)=\(\dfrac{y}{-21}\)=\(\dfrac{28}{49}\).
b) \(\dfrac{x}{7}\)=\(\dfrac{9}{y}\) , x > y.
c) \(\dfrac{x}{15}\)=\(\dfrac{3}{y}\) , x < y < 0
Tính:
a) \(\dfrac{-5}{9}\)\(+\dfrac{8}{15}+\dfrac{-2}{11}+\dfrac{4}{-9}+\dfrac{7}{15}\)
b)\(\left(\dfrac{-5}{12}+\dfrac{6}{11}\right)+\left(\dfrac{7}{17}+\dfrac{5}{11}+\dfrac{5}{12}\right)\)
c) A= \(49\dfrac{8}{23}-\left(5\dfrac{7}{32}+14\dfrac{8}{23}\right)\)
d) C= \(\dfrac{-3}{7}.\dfrac{5}{9}+\dfrac{4}{9}.\dfrac{-3}{7}+2\dfrac{3}{7}\)
\(a,\dfrac{-8}{5}:\left(1+\dfrac{2}{3}\right)\) \(b,\dfrac{7}{5}x\dfrac{15}{49}-\left(\dfrac{4}{5}+\dfrac{2}{3}\right):\dfrac{11}{5}\)
\(c,\dfrac{1}{3}:\left(\dfrac{2}{9}-\dfrac{7}{8}\right)\) \(d,\left(\dfrac{1}{6}-\dfrac{4}{5}\right):\dfrac{7}{5}\)
Giúp mik nha:>>
(11\(\dfrac{7}{18}\) - 9\(\dfrac{13}{18}\)): x - 1\(\dfrac{2}{33}\) : \(\dfrac{7}{11}\) = 1\(\dfrac{2}{3}\)
Tính hợp lý nếu có thể:
a) \(\dfrac{2}{9}+\dfrac{-3}{10}+\dfrac{-7}{10}\)
b) \(\dfrac{-11}{6}+\dfrac{2}{5}+\dfrac{-1}{6}\)
c) \(\dfrac{27}{13}-\dfrac{106}{111}+\dfrac{-5}{111}\)
d) \(\dfrac{12}{11}-\dfrac{-7}{19}+\dfrac{12}{19}\)
Viết tập hợp A các số tự nhiên x sao cho:
a, \(\dfrac{-36}{9}\) ≤ x < \(\dfrac{-15}{5}\)
b, \(\dfrac{-27}{3}\) < x ≤ \(\dfrac{12}{4}\)
c, \(\dfrac{-21}{7}\) < x < \(\dfrac{-12}{6}\)
Tìm số nguyên x, y biết:
\(a,\dfrac{x}{5}=\dfrac{-18}{10}\) b, \(\dfrac{6}{x-1}=\)\(\dfrac{-3}{7}\) c, \(\dfrac{y-3}{12}\)=\(\dfrac{3}{y-3}\) d, \(\dfrac{x}{25}\)=\(\dfrac{-5}{x^2}\)
Tìm x, y, z, t ∈ Z biết:
a, \(\dfrac{5}{x}=\dfrac{-10}{12}\) b, \(\dfrac{4}{-6}=\dfrac{x+3}{9}\) c, \(\dfrac{x-1}{25}=\dfrac{4}{x-1}\) d, \(\dfrac{x+1}{y}=\dfrac{-3}{5}\)
e, \(\dfrac{-12}{6}=\dfrac{x}{5}=\dfrac{-y}{3}=\dfrac{Z}{-17}=\dfrac{-t}{-9}\)
h, \(\dfrac{-24}{-6}=\dfrac{x}{3}=\dfrac{4}{y^2}=\dfrac{Z^3}{-2}\)
1. tìm các số chưa biết :
a) \(\dfrac{4}{3}\)= \(\dfrac{8}{x}\)=\(\dfrac{-y}{21}\)=\(\dfrac{-40}{z}\)=\(\dfrac{16}{t}\)=\(\dfrac{y}{111}\)
b) \(\dfrac{-7}{6}=\dfrac{x}{18}=\dfrac{-98}{y}=\dfrac{14}{y}=\dfrac{-14}{z}=\dfrac{t}{102}=\dfrac{4}{-78}\)
2. tìm x biết :
a) \(\dfrac{2}{x}=\dfrac{x}{8}\)
b) \(\dfrac{2x-9}{240}=\dfrac{39}{80}\)
c) \(\dfrac{x-1}{9}=\dfrac{8}{3}\)
mn giúp mk nha :>
Tìm x,y thuộc Z:
(x+1).(y+3)=6
(x-3).(y+1)=11
\(\dfrac{x}{9}\)-\(\dfrac{3}{y}\)=\(\dfrac{1}{18}\)
