\(\frac{1}{x}+\frac{1}{y}=\frac{1}{5}\)
1/x<1/5 =>x>5
Giải sử x<(=)y thì \(\frac{1}{x}+\frac{1}{y}<\left(=\right)\frac{2}{x}\) hay \(\frac{2}{10}<\left(=\right)\frac{2}{x}\) =>x<10
Vậy ta có 5<x<(=) 10
Thử x lần lượt với 6,7,8,9,10. Ta được cá trường hợp sau
TH1 x=6, y=30
TH2 x=10, y=10.
Các trương hợp kia đều cho tử khác 1
Bài 1 : Tính :
B = \(\frac{\frac{1}{2}+\frac{3}{4}-\frac{5}{6}}{\frac{1}{4}+\frac{3}{8}-\frac{5}{12}}+\frac{\frac{3}{4}+\frac{3}{5}-\frac{3}{8}}{\frac{1}{4}+\frac{1}{5}-\frac{1}{8}}\)
Bài 2 : tìm x và y
a) x3 - 36x = 0
b) \(\frac{x-3}{y-2}=\frac{3}{2}\)và x - y = 4 ( x , y \(\in\)Z )
tìm các cặp số nguyên x,y sao cho:
a)\(\frac{x}{3}-\frac{4}{y}=\frac{1}{5}\)
b)\(\frac{5}{x-1}-\frac{y-1}{3}=\frac{1}{6}\)
c)\(\frac{x}{2}+\frac{y}{3}=\frac{x+y}{2+3}\)
Bài 1: Tìm x biết:
a. \(\frac{5}{1.6}+\frac{5}{6.11}+...+\frac{5}{\left(5x+1\right)\left(5x+6\right)}=\frac{2010}{2011}\)
b. \(\frac{7}{x}+\frac{4}{5.9}+\frac{4}{9.13}+\frac{4}{13.17}+..+\frac{4}{41.45}=\frac{29}{45}\)
c. \(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{1}{x\left(x+2\right)}:2\)
d. (x-20) . \(\frac{\frac{1}{2}+\frac{1}{3}+..+\frac{1}{2000}}{\frac{1}{199}+\frac{2}{198}+\frac{3}{197}+...+\frac{198}{2}+\frac{199}{1}}=\frac{1}{2000}\)
Bài 2:
\(\frac{a}{n\left(n+a\right)}=\frac{1}{n}-\frac{1}{n+a}\left(n,a\right)\in Nsao\)
Bài 3:
a)\(\frac{3}{x}+\frac{y}{3}=\frac{5}{6}\)
b) \(\frac{x}{3}-\frac{4}{y}=\frac{1}{5}\)
c) \(\frac{x}{2}+\frac{y}{3}=\frac{x+y}{2+3}\)
d) \(\frac{x-1}{9}+\frac{1}{3}=\frac{1}{y+2}\)
Tìm x,y \(\in\)Z thỏa mã:
a. \(\frac{1}{x}+\frac{y}{6}=\frac{1}{2}\)
b.\(\frac{x}{2}-\frac{2}{y}=\frac{1}{5}\)
c.\(\frac{x-1}{9}+\frac{1}{3}=\frac{1}{y+2}\)
d.\(\frac{x}{3}-\frac{4}{y}=\frac{1}{5}\)
Giup mk vs mk cần gấp câu trả lời
Tìm x,y \(\in\)Z thỏa mã:
a. \(\frac{1}{x}+\frac{y}{6}=\frac{1}{2}\)
b.\(\frac{x}{2}-\frac{2}{y}=\frac{1}{5}\)
c.\(\frac{x-1}{9}+\frac{1}{3}=\frac{1}{y+2}\)
d.\(\frac{x}{3}-\frac{4}{y}=\frac{1}{5}\)
Giup mk vs mk cần gấp câu trả lời
1) \(\frac{24}{-12}=\frac{x}{5}=\frac{-y}{3}\)Tìm x và y
2) \(\frac{1}{3}+\frac{-2}{5}+\frac{1}{6}+\frac{-5}{25}\le\frac{x}{10}< \frac{-3}{4}+\frac{4}{14}+\frac{-2}{8}+\frac{-3}{5}+\frac{5}{7}\)Tìm x
3) \(\frac{8.x+18}{2.x+6}\)Tìm x
Tim x,y\(\in\) z biet :
a)\(\frac{x}{3}-\frac{2}{y}=\frac{1}{5}\) b)\(\frac{2}{x}-\frac{y}{3}=\frac{5}{6}\)
c)\(\frac{5}{x}-\frac{y}{3}=\frac{1}{6}\) d) \(\frac{x}{6}-\frac{2}{y}=\frac{1}{4}\)
\(Bài1:x+y=\frac{1}{2},y+z=\frac{1}{3},z+x=\frac{1}{4}\)
\(Bai2:\frac{x-1}{99}+\frac{x-2}{98}+\frac{x-5}{95}=3+\frac{1}{99}+\frac{1}{98}+\frac{1}{95}\)
Bài 1: \(\left(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+\frac{1}{5}-...+\frac{1}{49}-\frac{1}{50}\right):\left(\frac{1}{25}+\frac{1}{26}+...+\frac{1}{50}\right)\)
Bài 2: Tìm \(x;y\)biết:
\(\frac{x-3}{y-2}=\frac{3}{2}\)và \(x-y=4\)
bài 1 tim x y thuộc z
\(\frac{3}{x-5}=\frac{x-5}{27}\)
\(\frac{3}{x}=\frac{y}{35}=\frac{-36}{84}\)
\(\frac{3x+1}{-2}=\frac{-8}{3x+1}\)
\(\frac{3}{x-5}=\frac{-4}{x+2}\)
