tính
a,(1+8/10).(1+8/22).(1+8/36).(1+8/52)................(1+8/8352)
b,2.4+3.5+4.6+5.7+6.8+...............+97.99+98.100
tìm GTNN của A= |x^2+5| +(2y-3)\(^4\)
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A = 13/21.2/11 + 13/21.9/11 + 8/21
= (13/21) + (13/21) + (8/21)
= (13 + 13 + 8)/21
= 34/21
B = (1 - 1/5)(1 - 2/5)(1 - 3/5)...(1 - 9/5)
= (4/5)(3/5)(2/5)(1/5)(0/5)(-1/5)(-2/5)(-3/5)(-4/5)
= 0
C = (1 - 1/2)(1 - 1/3)(1 - 1/4)...(1 - 1/50)
= (1/2)(2/3)(3/4)(4/5)...(49/50)
= 1/50
D = (2^2/1.3) * (3^2/2.4) * (4^2/3.5) * (5^2/4.6) * (6^2/5.7)
= (4/3) * (9/8) * (16/15) * (25/23) * (36/35)
= 0.979
2A=2+2^2+2^3-2^4+...+2^2017
2A+A=2+1+2^2+2+2^2+2^3-2^3+2^4-2^4+...+2^2017-2^2016
3A=1+2^2+2^3+2^2017
A=(1+2^2+2^3+2^2017)/3
Minh giai 1 bai thoi nha
Nho k cho minh voi
a) \(A=1-2+2^2-2^3+2^4-2^5+.................+2^{2016}\)
\(\Rightarrow2A=2\left(1-2+2^2-2^3+2^4-2^5+............+2^{2016}\right)\)
\(\Rightarrow2A=2-2^2+2^3-2^4+2^5-2^6+...........+2^{2017}\)
\(\Rightarrow2A-A=\left(2-2^2+2^3-2^4+.........+2^{2016}\right)-\left(1-2+2^3+2^4-2^5+.....+2^{2017}\right)\)\(\Rightarrow A=2^{2017}-1\)
Câu a xong đã, câu b tính sau :P
Answer:
\(\left(1+\frac{8}{10}\right).\left(1+\frac{8}{22}\right).\left(1+\frac{8}{36}\right)...\left(1+\frac{8}{8352}\right)\)
\(=\frac{18}{10}.\frac{30}{22}.\frac{44}{36}...\frac{8360}{8352}\)
\(=\frac{2.9.3.10.4.11....88.95}{1.10.2.11.3.12...87.96}\)
\(=\frac{\left(2.3.4...8\right).\left(9.10.11...95\right)}{\left(1.2.3...87\right).\left(10.11...96\right)}\)
\(=\frac{9.88}{96}\)
\(=\frac{3}{4}\)