Đại số lớp 6
Các câu hỏi tương tự
Chứng Minh Rằng A=\(\dfrac{1}{1+3}+\dfrac{1}{1+3+5}+\dfrac{1}{1+3+5+7}+...+\dfrac{1}{1+3+5+...+2017}\)\(< \dfrac{3}{4}\)
BT1: Tính
3) \(\dfrac{\dfrac{2}{5}+\dfrac{2}{7}-\dfrac{2}{11}}{\dfrac{3}{5}+\dfrac{3}{7}-\dfrac{3}{11}}+\dfrac{\dfrac{1}{4}-\dfrac{1}{5}+\dfrac{1}{7}}{\dfrac{3}{4}-\dfrac{3}{5}+\dfrac{3}{7}}\)
6 tháng 8 2017 lúc 10:10
tìm x
a\(\dfrac{5x-3}{3-2x}=\dfrac{2}{3}\)
b\(\left(\dfrac{4}{5}x+\dfrac{2}{3}\right)\div\dfrac{3}{4}=2\)
c\(\dfrac{3}{4}x-\dfrac{1}{3}=\dfrac{3}{5}\)
d\(\dfrac{2}{3}-\dfrac{3}{5}\div x=\dfrac{1}{4}\)
giúp mình nhé
a)x=\(\dfrac{1}{4}+\dfrac{2}{13}\)
b)\(\dfrac{x}{3}=\dfrac{2}{3}+\dfrac{-1}{7}\)
c)\(\dfrac{-8}{3}+\dfrac{-1}{3}\le x\le\dfrac{-2}{7}+\dfrac{-5}{7}\)
d)\(\dfrac{-5}{6}+\dfrac{8}{3}\dfrac{29}{-x}\le x\le\dfrac{-1}{2}+2+\dfrac{5}{2}\)
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
3) \(\dfrac{2}{3}-\left(-\dfrac{1}{4}\right)+\dfrac{3}{5}-\dfrac{7}{45}-\left(-\dfrac{5}{9}\right)+\dfrac{1}{12}+\dfrac{1}{90}\)
4) B = \(\dfrac{1}{3}-\dfrac{3}{4}-\left(-\dfrac{3}{5}\right)+\dfrac{1}{64}-\dfrac{2}{9}-\dfrac{1}{36}+\dfrac{1}{15}\)
Giúp mk nhé các bạn!
So sánh
\(A=\dfrac{1}{2^2}+\dfrac{2}{2^3}+\dfrac{3}{2^4}+...+\dfrac{100}{2^{201}}\)
và \(B=\dfrac{1}{2^3}+\dfrac{1}{3^3}+\dfrac{1}{4^3}+...+\dfrac{1}{100^3}\)
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:
\(\dfrac{\dfrac{1}{3}-\dfrac{1}{5}-\dfrac{1}{7}}{\dfrac{2}{3}-\dfrac{2}{5}-\dfrac{2}{7}}\) + \(\dfrac{\dfrac{4}{7}-\dfrac{4}{9}+\dfrac{4}{11}}{\dfrac{3}{7}-\dfrac{1}{3}+\dfrac{9}{11}}\)=?