1, Tìm x, y thuộc Z:
a, \(\frac{x}{7}-\frac{1}{2}=\frac{1}{y+1}\)
b, \(\frac{5}{x}-\frac{y}{4}=\frac{1}{8}\)
c, \(\frac{2}{y}-\frac{1}{x}=\frac{8}{x\cdot y}+1\)
2, Tìm a, b, c thuộc N:
\(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=\frac{4}{3}\)
tìm x,y\(\in\)N* sao cho
a \(\frac{1}{x}+\frac{1}{y}=1\)
b \(\frac{1}{x}+\frac{y}{2}=\frac{5}{8}\)
Tìm x;y thuộc N :
25 - y2=8(x - 2009)2
Tìm x thuộc Z biết:
a)\(2x+\frac{1}{7}=\frac{1}{y}\)
b)\(\frac{5}{x}+\frac{y}{4}=\frac{1}{8}\)
c)\(\frac{x}{8}-\frac{1}{y}=\frac{1}{4}\)
1,Tìm cặp số nguyên x,y,z
\(\frac{1}{x}+\frac{1}{y}+\frac{1}{z}=1\)
2,Tìm x,y nguyên
\(\frac{5}{x}+\frac{y}{4}=\frac{1}{8}\)
Tìm cặp số nguyên x , y sao cho
a) \(\frac{y}{5}+\frac{1}{10}=\frac{1}{x}\)
b)\(\frac{x}{4}-\frac{1}{2}=\frac{3}{y}\)
tìm x; y nguyên biết:
a,\(\frac{1}{x+\frac{1}{y+\frac{1}{z}}}=1-\frac{1}{2+\frac{1}{3}}\)
b,\(\frac{x}{8}-\frac{2}{y}=\frac{3}{4}\)
c,\(\frac{x}{2}+\frac{3}{y}=\frac{5}{4}\)
Bài 1: Tìm x,y:
a) |x - 1| + |x + 3| = 4
b) |2x + 3| + |2x - 1| = \(\frac{8}{2\left(y-5\right)^2+2}\)
c) |x + 3| + |x + 1| = \(\frac{16}{\left|y-2\right|+\left|y+2\right|}\)
Bài 2: Tìm số nguyên x,y, biết:
a) \(\frac{1}{x}+\frac{1}{y}=\frac{1}{5}\)
b) \(x^2-2xy+y=0\)
1) A= \(\frac{\frac{3}{4}-\frac{3}{11}+\frac{3}{13}}{\frac{5}{7}-\frac{5}{11}+\frac{5}{13}}+\frac{\frac{1}{2}-\frac{1}{3}+\frac{1}{4}}{\frac{5}{4}-\frac{5}{6}+\frac{5}{8}}\)
b) Cho 3 so x,y,z la 3 so khac 0 thoa man dieu kien :
\(\frac{y+z-x}{x}=\frac{z+x-y}{y}=\frac{x+y-z}{z}\)
Hay tinh gia tri bieu thuc:\(B=\left(1+\frac{x}{y}\right)\left(1+\frac{y}{z}\right)\left(1+\frac{z}{x}\right)\)
b) Gọi 3 số cần tìm lần lượt là: x,y,z. Vì x,y,z tỉ lệ nghịch với 2;3;5 nên
\(2x=3y=5z\)
\(\hept{\begin{cases}\frac{x}{\frac{1}{2}}=\frac{y}{\frac{1}{3}}=\frac{z}{\frac{1}{5}}\\x+y+z=310\end{cases}}\)
\(\hept{\begin{cases}\frac{x}{\frac{1}{2}}=\frac{y}{\frac{1}{3}}=\frac{z}{\frac{1}{5}}=\frac{x+y+z}{\frac{1}{2}+\frac{1}{3}+\frac{1}{5}}=\frac{310}{\frac{31}{30}}=300\\x+y+z=310\end{cases}}\)
\(\hept{\begin{cases}\frac{x}{\frac{1}{2}}=300\\\frac{y}{\frac{1}{3}}=300\\\frac{z}{\frac{1}{5}}=300\end{cases}}\)
\(\hept{\begin{cases}x=\frac{1}{2}.300\\y=\frac{1}{3}.300\\z=\frac{1}{5}.300\end{cases}}\)
\(\hept{\begin{cases}x=150\\y=100\\z=60\end{cases}}\)