Cho A = 1/1.2+1/3.4+1/5.6+.........+1/199.200
Cho B= 1/101.200+1/102.199+.........1/1999.102+1/200.101
tính A/B
Những câu hỏi liên quan
cho A= 1/1.2+1/3.4+...+1/199.200
B= 1/101.200+1/102.199+...+1/199.102+1/200.101
tính A/B
Cho A = \frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+.....+\frac{1}{199.200}1.21+3.41+5.61+.....+199.2001
B= \frac{1}{101.200}+\frac{1}{102.199}+.....+\frac{1}{200.101}101.2001+102.1991+.....+200.1011
Tính A:B
cho A=1/1.2+1/3.4+...+1/199.200 và B=1/101.200+1/102.199+...+1/199.102+1/200.101
Cho E=301/101.200+301/102.199+301/103.198+...+301/200.101 và F=1/1.2+1/3.4+1/5.6+...+1/199.200
Chứng minh E:F có giá trị là STN
Cho A = \(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+.....+\frac{1}{199.200}\)
B= \(\frac{1}{101.200}+\frac{1}{102.199}+.....+\frac{1}{200.101}\)
Tính A:B
Cho :
A=\(\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{199.200}\)
B=\(\frac{1}{101.200}+\frac{1}{102.199}+...+\frac{1}{199.102}\)
Hãy tính \(\frac{A}{B}\)
Cho : \(A=\frac{1}{1.2}+\frac{1}{3.4}+\frac{1}{5.6}+...+\frac{1}{199.200}\)
\(B=\frac{1}{101.200}+\frac{1}{102.199}+\frac{1}{103.198}+...+\frac{1}{200.101}\)
Tính\(\frac{A}{B}\)
ai giải đc chỉ mình với
Cho \(A=\frac{1}{1.2}+\frac{1}{3.4}+...+\frac{1}{199.200}\)
và \(B=\frac{1}{101.200}+\frac{1}{102.199}+\frac{1}{103.198}+....+\frac{1}{200.101}\)
Chứng tỏ rằng \(\frac{2A}{B}\) là 1 số nguyên
a) A = 1/1.2+ 1/3.4+ 1/5.6+...+ 1/99.100
CMR: 7/12<A< 5/6
b) CMR: 1/1.2+ 1/3.4+ 1/5.6+...+1/49.50 = 1/26+ 1/27+ 1/28+...+1/50
a)A = 1 / (1*2) + 1 / (3*4) + ... + 1 / (99*100) > 1 / (1*2) + 1 / (3*4) = 1 / 2 + 1 / 12 = 7 / 12 ♦
A = 1 / (1*2) + 1 / (3*4) + ... + 1 / (99*100) = (1 - 1 / 2) + (1 / 3 - 1 / 4) + ... + (1 / 99 - 100) =
(1 - 1 / 2 + 1 / 3) - (1 / 4 - 1 / 5) - (1 / 6 - 1 / 7) - ... - (1 / 98 - 1 / 99) - 1 / 100 <
1 - 1 / 2 + 1 / 3 = 5 / 6 ♥
♦, ♥ => 7 / 12 < A < 5 / 6
b)ta có:
1/1.2+1/3.4+1/5.6+...+1/49.50
=>1-1/2+1/3-1/4+1/5-1/6+...+1/49-1/50
=>(1+1/3+1/5+1/7+...+1/49)-(1/2+1/4+1/6+...+1/50)
=>(1+1/2+1/3+...+1/49+1/50)-(1/2+1/4+1/6+...+1/50).2
=>(1+1/2+1/3+...+1/49+1/50) -( 1+1/2+1/3+...+1/25)
=>1/26+1/27+1/28+...+1/50=1/26+1/27+1/28+...+1/50
hay 1/1.2+1/3.4+1/5.6+...+1/49.50=1/26+1/27+1/28+...+1/50
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