Tìm 2 số hữu tỉ \(x\) và \(y\) \(\left(y\ne0\right)\) biết rằng \(x\)\(-\)\(y\)\(=\)\(x\)\(y\)\(=\)\(x\)\(:\)\(y\)
\(\frac{1}{6}\).\(\frac{1}{12}\).\(\frac{1}{20}\).\(\frac{1}{30}\).\(\frac{1}{42}\).\(\frac{1}{56}\).\(\frac{1}{72}\).\(\frac{1}{90}\).\(\frac{1}{110}\)=?
tìm x biết :
a, ( \(\frac{1}{7}\)\(x\) - \(\frac{2}{7}\)) . ( -\(\frac{1}{5}\)\(x\) + \(\frac{3}{5}\)) . ( \(\frac{1}{3}\)\(x\) + \(\frac{4}{3}\)) =0
b, \(\frac{1}{6}x\) + \(\frac{1}{10}x\) - \(\frac{4}{15}x\) + 1 = 0
Cho tổng A = 1 + 32 + 34 + 36 +…+ 32008
Tính giá trị biểu thức: B = 8A - 32010
Chứng minh rằng:\(\frac{1}{1.2}\)+\(\frac{1}{3.4}\)+\(\frac{1}{5.6}\)+...+\(\frac{1}{49.50}\)=\(\frac{1}{26}\)+\(\frac{1}{27}\)+\(\frac{1}{28}\)+...+\(\frac{1}{50}\)
A= \(\frac{1}{101}\)+\(\frac{1}{102}\)+\(\frac{1}{103}\)+...+\(\frac{1}{150}\)
chứng minh rằng \(\frac{1}{3}\)<A<\(\frac{1}{2}\)
Thu gọn: \(2^{100}\)+\(2^{99}\)+\(2^{98}\)+...+\(2^2\)+\(2\)+\(1\) = ?
Xác định điều kiện số hữu tỉ x thỏa mãn trong mỗi trường hợp sau:
a.\(\frac{3}{8}\)+x-2\(\frac{1}{3}\) > \(\frac{5}{4}\)
b. -4,25 - (x-\(\frac{3}{5}\)) \(\le\) 3\(\frac{1}{2}\)- 0,15
c.\(\frac{5}{9}\)+ (- \(\frac{7}{6}\)) < x+\(\frac{2}{3}\)< 4-1,75
d. -\(\frac{5}{3}\)<\(\frac{7}{6}\)- ( x-\(\frac{1}{5}\)) \(\le\)\(\frac{11}{13}\)
tim x
1)\(\frac{4}{15}\)+\(\frac{1}{6}\)-\(\frac{4}{9}\)>\(\frac{2}{3}\)-x-\(\frac{1}{4}\)
2)4-\(1\frac{1}{3}\)<x+\(\frac{1}{5}\)<\(12\frac{2}{7}\)-\(3\frac{3}{8}\)
3)\(\frac{1}{8}\)+ x-\(2\frac{2}{3}\)>\(1\frac{1}{3}\)
4)-4,15<x-\(\frac{2}{5}\)<\(1\frac{1}{2}\)-0,75