A=-3-5-...-49
Số số hạng là (49-3):2+1=46:2+1=23+1=24(số)
Tổng là: A=-(49+3)*24/2=-52*12=-624
=>\(B=\dfrac{1-624}{90}=\dfrac{-623}{90}\)
Thực hiện phép tính:
\(A=\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
\(B=\dfrac{1-\dfrac{1}{\sqrt{49}}+\dfrac{1}{49}-\dfrac{1}{\left(7\sqrt{7}\right)^2}}{\dfrac{\sqrt{64}}{2}-\dfrac{4}{7}+\dfrac{2^2}{7^2}-\dfrac{4}{343}}\)
\(\sqrt{\dfrac{16}{49}}+\left(\dfrac{1}{2}\right)^3-\left|-\dfrac{4}{7}\right|-\dfrac{7}{8}\)
\(\left|\dfrac{1}{2}-\dfrac{3}{5}\right|\cdot\sqrt{9}+0.5\cdot\left(-2\dfrac{3}{5}\right)\)
\(\left(\dfrac{1}{4.9}+\dfrac{1}{9.14}+\dfrac{1}{14.19}+...+\dfrac{1}{44.49}\right)\dfrac{1-3-5-7-...-49}{89}\)
thực hiện phép tính
Tính:
\(A=\left(\dfrac{1}{4.9}+\dfrac{1}{9.14}+...+\dfrac{1}{44.49}\right).\dfrac{1-3-5-7-...-49}{89}\)
Giải chi tiết dùm mik nha. Thankss
a, \(5^6\) : \(5^5\) + \(\left(\dfrac{4}{9}\right)^0\) b,\(\left(\dfrac{3}{7}\right)^{21}\) : \(\left(1-\dfrac{40}{49}\right)^3\) c, 3.\(\left(\dfrac{2}{3}\right)^3\) -\(\left(\dfrac{-52}{3}\right)^0\) +\(\dfrac{4}{9}\)
Mọi người giúp mình với
\(x\) x {\(\dfrac{1}{4}\) + \(\dfrac{1}{5}\)} - {\(\dfrac{1}{7}\) + \(\dfrac{1}{8}\)}
2 : \(x\) = \(x\) : \(\dfrac{8}{49}\)
so sánh các số sau : \(a=\dfrac{35}{49};b=\sqrt{\dfrac{5^2}{7^2}};c=\dfrac{\sqrt{5^2}+\sqrt{35^2}}{\sqrt{7^2}+\sqrt{49^2}};d=\dfrac{\sqrt{5^2}-\sqrt{35^2}}{\sqrt{7^2}-\sqrt{49^2}}\)
\(99^{99}\)-\(\left\{1,\left(3\right)-\left[5\times2^3-\left(-7^2\right)+\dfrac{1}{3}+99^9\times\left(27^4-81^3-99^{90}\right)\right]\right\}\)
Tính giá trị của các biểu thức sau 1) \(A=1+2+2^2+...+2^{2015}\) 2) \(B=\left(\dfrac{1}{4}-1\right)\cdot\left(\dfrac{1}{9}-1\right)\cdot\left(\dfrac{1}{16}-1\right)\cdot\cdot\cdot\cdot\cdot\left(\dfrac{1}{400}-1\right)\) 3) \(C=\left(\dfrac{1}{4\cdot9}+\dfrac{1}{9\cdot14}+\dfrac{1}{14\cdot19}+...+\dfrac{1}{44\cdot49}\right)\cdot\dfrac{1-3-5-7-...-49}{89}\) 4) \(D=\dfrac{2^{12}\cdot3^5-4^6\cdot9^2}{\left(2^2\cdot3\right)^6+8^4\cdot3^5}-\dfrac{5^{10}\cdot7^3-25^5\cdot49^2}{\left(125\cdot7\right)^3+5^9\cdot14^3}\) 5) \(E=\dfrac{\dfrac{1}{2003}+\dfrac{1}{2004}-\dfrac{1}{2005}}{\dfrac{5}{2003}+\dfrac{5}{2004}-\dfrac{5}{2005}}-\dfrac{\dfrac{2}{2002}+\dfrac{2}{2003}-\dfrac{2}{2004}}{\dfrac{3}{2002}+\dfrac{3}{2003}-\dfrac{3}{2004}}\) 6) Cho 13+23+...+103=3025 Tính S= 23+43+63+...+203
