P = \(1+\dfrac{1}{2}\left(1+2\right)+\dfrac{1}{3}\left(1+2+3\right)+\dfrac{1}{4}\left(1+2+3+4\right)+....+\dfrac{1}{16}\left(1+2+3+...+16\right)\)
Thực hiện tính
M=\(1+\dfrac{1}{2}\cdot\left(1+2\right)+\dfrac{1}{3}\cdot\left(1+2+3\right)+\dfrac{1}{4}\cdot\left(1+2+3+4\right)+...+\dfrac{1}{16}\cdot\left(1+2+3+...+16\right)\)
Tính :
P = 1 +\(\dfrac{1}{2}+\left(1+2\right)+\dfrac{1}{3}\left(1+2+3\right)+\dfrac{1}{4}\left(1+2+3+4\right)+.....+\dfrac{1}{16}\left(1+2+3+....+6\right)\)
Tính
\(\left(\dfrac{1}{2}\right)^{15}.\left(\dfrac{1}{2}\right)^{20}\)
\(\left(\dfrac{1}{9}\right)^{25}:\left(\dfrac{1}{3}\right)^{30}\)
\(\left(\dfrac{1}{16}\right)^3:\left(\dfrac{1}{8}\right)^2\)
\(\left(x^3\right)^2:\left(x^2\right)^3\) ( với x khác o )
Tính hợp lí nếu có thể
a) \(\left(\dfrac{5}{7}-\dfrac{7}{5}\right)-\left[\dfrac{1}{2}-\left(-\dfrac{2}{7}-\dfrac{1}{10}\right)\right]\)
b) \(\dfrac{2}{15}:\left(-5\dfrac{4}{5}\right).2\dfrac{5}{12}+\sqrt{1\dfrac{9}{16}}:\left(-\dfrac{3}{4}\right)\)
thực hiên phép tính :
a, \(\left(3^2\right)^2-\left(2^3\right)^2-\left(-5^2\right)^2\)
b, \(2^3+3.\left(-\dfrac{1}{2}\right)^0-\left(\dfrac{1}{2}\right)^2.4+\left(\left(-2\right)^2:\dfrac{1}{2}\right):8\)
c, \(\left(4.2^5\right):\left(2^3.\dfrac{1}{16}\right)\)
d, \(A=\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
Tìm tập hợp các số nguyên x thỏa mãn:
a) \(3\dfrac{1}{3}:2\dfrac{1}{2}-1< x< 7\dfrac{2}{3}.\dfrac{3}{7}+\dfrac{5}{2}\)
b) \(\dfrac{1}{2}-\left(\dfrac{1}{3}+\dfrac{1}{4}\right)< x< \dfrac{1}{48}-\left(\dfrac{1}{16}-\dfrac{1}{6}\right)\)
Help me.
1. tìm x
a. x- \(\left(\dfrac{1}{3}\right)^3\)= \(\dfrac{-1}{3}\)
b. \(\left(\dfrac{4}{5}\right)^5.x=\left(\dfrac{4}{5}\right)^7\)
c. \(x+\left(\dfrac{1}{2}\right)^2=\dfrac{1}{16}\)
d. \(\left(3x+1\right)^3=-27\)
1, thực hiện phép tính
\(\dfrac{\left(\dfrac{2}{5}\right)^9.10^9-\left(\dfrac{-9}{4}\right)^5:\left(\dfrac{-3}{16}\right)^{10}}{4^{12}+16^9}\)
2,CMR:\(\dfrac{1}{2^2}+\dfrac{1}{3^2}+.......+\dfrac{1}{n^2}< \dfrac{2}{3}\)với n\(\ge\)4
