\(P=\dfrac{5}{5.10}+\dfrac{5}{10.15}+...+\dfrac{5}{95.100}\)
\(\Rightarrow P=\dfrac{1}{5}-\dfrac{1}{10}+\dfrac{1}{10}-\dfrac{1}{15}+...+\dfrac{1}{95}-\dfrac{1}{100}\)
\(\Rightarrow P=\dfrac{1}{5}-\dfrac{1}{100}\)
\(\Rightarrow P=\dfrac{19}{100}\)
Vậy \(P=\dfrac{19}{100}\)
Tính \(3\dfrac{1}{117}.\dfrac{1}{119}-\dfrac{4}{117}.5\dfrac{118}{119}-\dfrac{5}{117.119}+\dfrac{8}{39}\)
Nhanh nha
3. Tính giá trị của biểu thức \(A=3\dfrac{1}{117}.4\dfrac{1}{119}-1\dfrac{116}{117}.5\dfrac{118}{119}-\dfrac{5}{119}\)
Câu 3 Thực hiện phép tính::(2 điểm )
a/ \(\dfrac{x^2}{x+2}\) + \(\dfrac{2x}{x+2}\)
b/ \(\dfrac{5x+4}{3x+15}\) - \(\dfrac{x-2}{x+5}\)
a, T= (1-\(\dfrac{1}{2}\))+(1-\(\dfrac{1}{4}\))+(1-\(\dfrac{1}{8}\))+...+(1-\(\dfrac{1}{512}\))+(1-\(\dfrac{1}{1024}\))+(1-\(\dfrac{1}{2048}\))+(1-\(\dfrac{1}{4096}\))
b, 4*5100*(\(\dfrac{1}{5}\)+\(\dfrac{1}{5^2}\)+\(\dfrac{1}{5^3}\)+...+\(\dfrac{1}{5^{100}}\))+1
Tính giá trị biểu thức:
a) \(\dfrac{11}{125}-\dfrac{17}{18}-\dfrac{5}{7}+\dfrac{4}{9}+\dfrac{17}{14}\)
b) \([9,6\left(\dfrac{3}{4}-\dfrac{5}{2}\right)^2][6\left(\dfrac{-2}{3}\right)+12\left(\dfrac{-2}{3}\right)^2+18\left(\dfrac{-2}{3}\right)]\left(\dfrac{3}{2}\right)^2\)
Rút gọn biểu thức Q với x =5; và x =
– 5
Q=\(\left(\dfrac{1}{x+5}+\dfrac{1}{x-5}\right):\dfrac{2x}{x^2-25}\)
1, Tính
a) \(\dfrac{3x^2-5}{x^2-5x}+\dfrac{5-15x}{5x-25}\)
b) \(\dfrac{4+x^3}{x-3}-\dfrac{2x+2x^2}{x-3}+\dfrac{2x-13}{x-3}\)
c) \(\dfrac{2}{x-5}+\dfrac{x-25}{\left(x+5\right)\left(x-5\right)}\)
d) \(\dfrac{2x+8}{x^2-12+1}+\dfrac{7}{x-2}\)
2. Tính giá trị biểu thức
A= \(2\left(x+1\right)+\left(3x+2\right)\left(3x-2\right)-9x^2\)
tại \(x=15\)
tìm x:
\(-1\dfrac{1}{56};\left(\dfrac{1}{8}-\dfrac{1}{7}\right)-\dfrac{22}{2x-0,5}=-1\dfrac{1}{30}:\left(\dfrac{1}{5}-\dfrac{1}{6}\right)\)
tính gt bt
a/\(P=\sqrt{1^3+\dfrac{1^2}{3}}+\sqrt{2^3+\dfrac{3^2}{5}}+\sqrt{3^3+\dfrac{5^2}{7}}+...+\sqrt{75^3+\dfrac{149^2}{151}}\)
