Đại số lớp 6
Các câu hỏi tương tự
Tính giá trị biểu thức :
\(\dfrac{1}{2}-\left(\dfrac{1}{3}+\dfrac{2}{3}\right)+\left(\dfrac{1}{4}+\dfrac{2}{4}+\dfrac{3}{4}\right)-\left(\dfrac{1}{5}+\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{4}{5}\right)+\left(\dfrac{1}{6}+\dfrac{2}{6}+\dfrac{3}{6}+\dfrac{4}{6}+\dfrac{5}{6}\right)-\left(\dfrac{1}{7}+\dfrac{2}{7}+\dfrac{3}{7}+\dfrac{4}{7}+\dfrac{5}{7}+\dfrac{6}{7}\right)+...+\left(100+...+\dfrac{99}{100}\right)\)
BT2: Tính nhanh
5) \(\dfrac{1}{7}.\dfrac{2}{5}+\dfrac{1}{7}.\dfrac{1}{5}+\dfrac{1}{7}.\dfrac{4}{5}\)
6) \(\dfrac{-3}{7}.\dfrac{19}{11}+\dfrac{-2}{7}.\dfrac{3}{11}+4\dfrac{6}{11}\)
BT3: Tìm x, biết
3) \(\dfrac{3}{4}.x-\dfrac{5}{3}.x=\dfrac{7}{12}\)
4) \(x-\dfrac{1}{7}=\) \(\dfrac{\dfrac{4}{2011}-\dfrac{4}{2013}+\dfrac{4}{99}}{\dfrac{5}{2011}-\dfrac{5}{2013}+\dfrac{5}{99}}+\dfrac{1}{2}\)
Các bạn giúp mk nhé
Tính:
a, A = 1+2-3-4+5+6-7-8 +........+2013+2014
b, B = (1+\(\dfrac{1}{2}\) ) . ( 1+\(\dfrac{1}{3}\) ) . ( 1+\(\dfrac{1}{4}\) ) ....... (1+\(\dfrac{1}{2015}\))
CMR :
\(A=\dfrac{1}{5}+\dfrac{1}{6}+\dfrac{1}{7}+....+\dfrac{1}{17}< 2\)
Chứng tỏ rằng: B=\(\dfrac{1}{2^2}+\dfrac{1}{3^2} +\dfrac{1}{4^2}+\dfrac{1}{5^2}+\dfrac{1}{6^2}+\dfrac{1}{7^2}+\dfrac{1}{8^2}\)<1
Cho A = \(1+\dfrac{1}{2}+\dfrac{1}{3}+\dfrac{1}{4}+...+\dfrac{1}{4026}\)
B = \(1+\dfrac{1}{3}+\dfrac{1}{5}+\dfrac{1}{7}+...+\dfrac{1}{4025}\)
So sánh \(\dfrac{A}{B}\)với \(1\dfrac{2013}{2014}\)
Bài 1: Thực hiện phép tính (hợp lý nếu có thể)
(6dfrac{4}{9}+3dfrac{7}{11})-4dfrac{4}{9}
1dfrac{1}{3}-2dfrac{5}{6}-dfrac{6}{11}+3:5%
4dfrac{3}{4}-0,37+dfrac{1}{8}-1,28-2,5+3dfrac{1}{12}
dfrac{5}{7}.dfrac{5}{11}+dfrac{5}{7}.dfrac{2}{11}-dfrac{5}{7}.dfrac{14}{11}
dfrac{left(2^3.5.7right).left(5^2.7^3right)}{left(2.5.7^2right)^2}
Đọc tiếp
Bài 1: Thực hiện phép tính (hợp lý nếu có thể)
\((6\dfrac{4}{9}+3\dfrac{7}{11})-4\dfrac{4}{9}\)
\(1\dfrac{1}{3}-2\dfrac{5}{6}-\dfrac{6}{11}+3:5\%\)
\(4\dfrac{3}{4}-0,37+\dfrac{1}{8}-1,28-2,5+3\dfrac{1}{12}\)
\(\dfrac{5}{7}.\dfrac{5}{11}+\dfrac{5}{7}.\dfrac{2}{11}-\dfrac{5}{7}.\dfrac{14}{11}\)
\(\dfrac{\left(2^3.5.7\right).\left(5^2.7^3\right)}{\left(2.5.7^2\right)^2}\)
Tính \(\dfrac{P}{A}\)biết :
P=\(\dfrac{2013}{2}+\dfrac{2013}{3}+\dfrac{2013}{4}+...+\dfrac{2013}{2014}\)
A = \(\dfrac{2013}{1}+\dfrac{2012}{2}+\dfrac{2011}{1}+....+\dfrac{1}{2013}\)