a: =>4/x=y/-21=4/7
=>x=7; y=-12
b: =>xy=63
mà x>y
nên \(\left(x,y\right)\in\left\{\left(9;7\right);\left(21;3\right);\left(63;1\right);\left(-7;-9\right);\left(-3;-21\right);\left(-1;-63\right)\right\}\)
c: =>xy=45
mà x<y<0
nên \(\left(x,y\right)\in\left\{\left(-45;-1\right);\left(-15;-3\right);\left(-9;-5\right)\right\}\)
Tìm các số nguyên x và y, biết:
a)\(\dfrac{x}{7}=\)\(\dfrac{6}{21}\) b)\(\dfrac{-5}{y}\)= \(\dfrac{20}{28}\)
c)\(\dfrac{-4}{8}=\)\(\dfrac{-7}{y}\)
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 các số nguyên x,y biết :
a). \(\dfrac{x}{2}\)=\(\dfrac{-5}{y}\). b). \(\dfrac{3}{x}\)=\(\dfrac{y}{4}\), trong đó x > y > 0.
c). \(\dfrac{3}{x-1}\)= y+1. d). \(\dfrac{x+2}{5}\)=\(\dfrac{1}{y}\).
tìm x, y ϵ Z
\(\dfrac{x}{-3}\)=\(\dfrac{9}{4}\) và 2x+y=-4
4 tìm 2 stn (a,b)=1 bt
\(\dfrac{5a+7b}{6a+5b}\)=\(\dfrac{29}{28}\)
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, \(\dfrac{-24}{-6}=\dfrac{x}{3}=\dfrac{4}{y^2}=\dfrac{Z^3}{-2}\)
Tìm các số nguyên x,y biết :
a) \(\dfrac{x}{3}=\dfrac{4}{y}\) ; b) \(\dfrac{x}{y}=\dfrac{2}{7}\) .
Tìm các số nguyên x,y biết:
a)\(\dfrac{6}{2x+1}=\dfrac{2}{7}\)
b) \(\dfrac{24}{7x-3}=\dfrac{-4}{25}\)
c) \(\dfrac{4}{x-6}=\dfrac{y}{24}=\dfrac{-12}{18}\)
d) \(\dfrac{-1}{5}\le\dfrac{x}{8}\le\dfrac{1}{4}\)
e) \(\dfrac{x+46}{20}=x\dfrac{2}{5}\)
f) \(y\dfrac{5}{y}=\dfrac{86}{y}\) ( \(x\dfrac{2}{5};y\dfrac{5}{y}\) là các hỗn số)
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 biết:
a. \(\dfrac{x}{9}=\dfrac{4}{x}\) b. \(\dfrac{x+1}{3}=\dfrac{3}{x+1}\)
