Tuyển Cộng tác viên Hoc24 nhiệm kì 26 tại đây: https://forms.gle/dK3zGK3LHFrgvTkJ6
Tính.
a)A=1/1.3.5+1/3.5.7+1/5.7.9+...+1/97.99.101
b)B=2^2019-2^2018-2^2017-...-2+1
c)C=1/1.2+1/3.4+...+1/49.50-1/50-1/49-...-1_2
d)D=1/2!+5/3!+11/4!+..+99.100-1/100!
a, Cho A= 1/99 + 2/98 + 3/47 + .......... + 98/2 + 99/1
B= 1/2 + 1/3 + 1/4 + ..........+ 1/99 + 1/100
Tính B/A
b, Cho A= 1/49 + 2/48 + 3/47 +.......+ 48/2 +49/1
B= 1 + 2/3 + 2/4 +......+ 2/49 + 2/50
Tính A/B
Thực hiện phép tính:
\(A=\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}-\dfrac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
\(B=\dfrac{1-\dfrac{1}{\sqrt{49}}+\dfrac{1}{49}-\dfrac{1}{\left(7\sqrt{7}\right)^2}}{\dfrac{\sqrt{64}}{2}-\dfrac{4}{7}+\dfrac{2^2}{7^2}-\dfrac{4}{343}}\)
Tính: M= 1/1.3.5+1/3.5.7+1+....+1/95.97.99
\(B=\frac{2^{12}.3^5-4^6.9^2}{\left(2^2.6\right)^6+8^4.3^5}-\frac{5^{10}.7^3-25^5.49^2}{\left(125.7\right)^3+5^9.14^3}\)
\(C=\frac{1^2}{1.2}.\frac{2^2}{2.3}.\frac{3^2}{3.4}.\frac{4^2}{4.5}\)
\(D=\frac{2}{3.5}+\frac{2}{5.7}+\frac{2}{7.9}+...+\frac{2}{97.99}\)
so sánh
a)A=1/2^1+1/2^2+1/2^3+...+1/2^49+1/2^50 với 1
b)B=1/3^1 +1/3^2+1/3^3...+1/3^99+1/3^100 với 1/2
c)C=1/4^1+1/4^2+1/4^3+...+1/4^999+1/4^1000 với 1/3
b) 49^6.5-7^11/(-7)^10.5+2.49^5
2^12.3^5-4^6.3^6/2^12.9^3+8^4.3^5
1) Tinh gia tri cua bieu thuc:
A=\(\frac{\left(1+2+...+100\right)\left(\frac{1}{2}-\frac{1}{3}-\frac{1}{4}-\frac{1}{5}\right)\left(2,4.42-21.4,8\right)}{1+\frac{1}{2}+\frac{1}{3}+\frac{1}{4}+...+\frac{1}{100}}\)
B=\(\frac{4^6.9^5+6^9.120}{-8^4.3^{12}+6^{11}}\)
Cho A = 3.5.7...9.(1+1/3+1/5+1/7+...+1/97+1/99)
Chứng tỏ rằng A chia hết cho 4
