\(=\frac{2\left(\frac{2}{111}+\frac{2}{123}+\frac{2}{999}\right)}{\frac{2}{111}+\frac{2}{123}+\frac{2}{999}}\)
\(=2\)
\(=\frac{2\left(\frac{2}{111}+\frac{2}{123}+\frac{2}{999}\right)}{\frac{2}{111}+\frac{2}{123}+\frac{2}{999}}\)
\(=2\)
\(A=\frac{\frac{4}{111}+\frac{4}{123}-\frac{4}{999}}{\frac{2}{111}+\frac{2}{123}-\frac{2}{999}}\)
\(\frac{4}{\frac{111}{\frac{2}{111}+}}+\frac{4}{\frac{123}{\frac{2}{123}+}}-\frac{4}{\frac{999}{\frac{2}{999}}}\)
\(CMR:\frac{1}{11-2}=\frac{12}{111-3}=\frac{123}{1111-4}=\frac{1234}{11111-5}\)
tính giá trị :\(Q=\left(\frac{1}{99}+\frac{12}{999}+\frac{123}{999}\right)\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)\)
Tinh gia tri bieu thuc :
\(\left(\frac{1}{99}+\frac{12}{999}+\frac{123}{999}\right)\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\right)\)
tính nhanh:
B=(\(\frac{1}{99}+\frac{12}{999}-\frac{123}{9999}\)).(\(\frac{1}{2}-\frac{1}{3}-\frac{1}{6}\))
Tính\(\frac{1}{1}.\frac{1}{2}+\frac{1}{2}.\frac{1}{3}+\frac{1}{3}.\frac{1}{4}+............+\frac{1}{998}.\frac{1}{999}+\frac{1}{999}.\frac{1}{1000}\)
Tính:
D=\(\frac{1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+....+\frac{1}{999}-\frac{1}{1000}}{500-\frac{500}{501}-\frac{501}{502}-.....-\frac{999}{1000}}\)
Tính giá trị biểu thức bằng cách thuận tiện nhất:
a) \(\frac{3^4-1^2}{4^3-2^1}+\frac{7^8-5^6}{8^7-6^5}+...+\frac{995^{996}-993^{994}}{996^{995}-994^{993}}+\frac{999^{1000}-997^{998}}{1000^{999}-998^{997}}\)
b)\(\frac{4^3}{3^4}-\frac{2^1}{1^2}+\frac{8^7}{7^8}-\frac{6^5}{5^6}+...+\frac{996^{995}}{995^{996}}-\frac{994^{993}}{993^{994}}+\frac{1000^{999}}{999^{1000}}-\frac{998^{997}}{997^{998}}\)
c)\(\frac{3^4}{4^3}-\frac{1^2}{2^1}+\frac{7^8}{8^7}-\frac{5^6}{6^5}+...+\frac{995^{996}}{996^{995}}-\frac{993^{994}}{994^{993}}+\frac{999^{1000}}{1000^{999}}-\frac{997^{998}}{998^{997}}\)
Không sao đâu,các bạn có thể giải từng câu một nhưng phải nhanh lên nhé!
(Các bạn nhớ ghi cách làm nhé!)