Bài 1 :Tìm a,b biết :
\(a+b=3.\left(a-b\right)=\)\(2\frac{a}{b}\)
Bài 2 :
\(A=50+\frac{50}{3}+\frac{25}{3}+\frac{20}{4}+\frac{10}{5}+\frac{100}{67}+...+\frac{100}{98.99}+\frac{1}{99}\)
1) Hãy tính:
A= (1 + 2 +3 + ... + 100) - (\(\frac{1}{2}\)+ \(\frac{2}{3}\)+ \(\frac{3}{4}\)+ ... + \(\frac{49}{50}\))
B=( \(\frac{1}{2\frac{3}{4}}\)+ \(\frac{1}{3\frac{4}{5}}\)+ \(\frac{1}{4\frac{5}{6}}\)+ ... + \(\frac{1}{98\frac{99}{100}}\)) - ( \(\frac{1}{2}\). \(\frac{3}{4}\)\(\frac{5}{6}\)... \(\frac{99}{100}\))
2) Tìm x để:
a) \(\left(x+10\right).\left(x+20\right)...\left(x+500\right)=5000000\)
b) \(\frac{1}{2}\)\(x\) + \(\frac{3}{4}\)\(x\) + ... + \(\frac{100}{101}\)\(x\) = \(5000\)
\(\frac{\sqrt{x-5}}{45}\). \(\frac{\frac{6}{7}}{\sqrt{4^{75}}+25}\) - \(\left(\frac{4}{5}+\frac{6}{7}+...+\frac{50}{51}\right)\) = \(300x\)
Cho \(P=\frac{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+..+\frac{99}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+..+\frac{1}{100}}\)và \(Q=\frac{92-\frac{1}{9}-\frac{2}{10}-\frac{3}{11}-..-\frac{92}{100}}{\frac{1}{45}+\frac{1}{50}+\frac{1}{55}+..+\frac{1}{500}}\)
a)Tính P,Q b) Tính tỉ số % của P và 3Q
Cho \(M=\frac{\frac{1}{99}+\frac{2}{98}+\frac{3}{97}+.......+\frac{99}{1}}{\frac{1}{2}+\frac{1}{3}+\frac{1}{4}....+\frac{1}{100}}\)
\(N=\frac{92-\frac{1}{9}-\frac{2}{10}-\frac{3}{11}-....-\frac{92}{100}}{\frac{1}{45}+\frac{1}{50}+\frac{1}{55}+.....+\frac{1}{495}+\frac{1}{500}}\)
Tính M; N
Tính \(1\frac{1}{2}+2\frac{2}{3}+3\frac{3}{4}+4\frac{4}{5}+...+50\frac{50}{51}+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{51}\)
Tìm x biết :
a) \(\frac{x+11}{10}+\frac{x+21}{20}+\frac{x+31}{30}=\frac{x+41}{40}+\frac{x+101}{50}\)
b) \(\frac{x+2}{42}+\frac{x+4}{22}=\frac{x+5}{23}+\frac{x+3}{43}\)
c) \(\frac{x-10}{20}+\frac{x-20}{10}+\frac{x-30}{5}=\frac{x-14}{4}\)
a,\(\frac{3^9-2^3.3^7+2^{10}.3^2-2^{13}}{3^{10}-2^2.3^7+2^{10}.3^3}\)
b,\(\left(-2\frac{1}{3}\right)^{100}.\left(-0,5\right)^{99}:\left(\frac{7}{3}\right)^{98}:\left(\frac{1}{4}\right)^{50}\)
Cmr:\(50< 1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{2^{100-1}}< 100\)
\(1\frac{1}{2}+2\frac{2}{3}+3\frac{3}{4}+...+50\frac{50}{51}+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...\frac{1}{51}\)