Bài 1:Tính bằng cách hợp lý:a)frac{8.4.125.25+96524+3476}{1+5+9+...+61+62,5-26}b)frac{5+55+555+5555}{9+99+999+9999}c)39,2.27+39,2.43+78,4.15d)frac{4}{17}.frac{3}{11}+frac{8}{11}.frac{4}{17}-frac{4}{17}e)(812,1.10,5-91.10,5).(41.11-4100.0,1-41)Bài 2:Tính nhanh các tổng sau:a)frac{1}{5.7}+frac{1}{7.9}+frac{1}{9.11}+...+frac{1}{57.59}b)left(frac{1}{2}+frac{1}{3}+frac{1}{4}+frac{1}{5}+frac{1}{6}+frac{1}{7}right)-left(frac{1}{3}+frac{1}{4}+frac{1}{5}+frac{1}{6}+frac{1}{7}+frac{1}{8}right)c)left(1-fra...
Đọc tiếp
Bài 1:Tính bằng cách hợp lý:
a)\(\frac{8.4.125.25+96524+3476}{1+5+9+...+61+62,5-26}\)
b)\(\frac{5+55+555+5555}{9+99+999+9999}\)
c)39,2.27+39,2.43+78,4.15
d)\(\frac{4}{17}.\frac{3}{11}+\frac{8}{11}.\frac{4}{17}-\frac{4}{17}\)
e)(812,1.10,5-91.10,5).(41.11-4100.0,1-41)
Bài 2:Tính nhanh các tổng sau:
a)\(\frac{1}{5.7}+\frac{1}{7.9}+\frac{1}{9.11}+...+\frac{1}{57.59}\)
b)\(\left(\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{1}{6}+\frac{1}{7}\right)-\left(\frac{1}{3}+\frac{1}{4}+\frac{1}{5}+\frac{1}{6}+\frac{1}{7}+\frac{1}{8}\right)\)
c)\(\left(1-\frac{1}{2}\right).\left(1-\frac{1}{3}\right).\left(1-\frac{1}{4}\right).\left(1-\frac{1}{5}\right)\cdot...\cdot\left(1-\frac{1}{2012}\right)\)
GẤP!GẤP!GẤP!MAI MIK NỘP RỒI!BẠN NÀO ĐẦU TIÊN MIK TIK CHO NHA!
*Lưu ý:Dấu chấm là dấu nhân đó
