so sánh ?
A=\(\frac{20^{10}+1}{20^{10}-1}\)và B=\(\frac{20^{10}+1}{20^{10}-3}\)
giúp ạ mình xin cảm ơn
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so sánh ?
A=\(\frac{20^{10}+1}{20^{10}-1}\)và B=\(\frac{20^{10}+1}{20^{10}-3}\)
giúp ạ mình xin cảm ơn
\(A=\dfrac{20^{10}+1}{20^{10}-1}=\dfrac{20^{10}-1}{20^{10}-1}+\dfrac{2}{20^{10}-1}=1+\dfrac{2}{20^{10}-1}\)
\(B=\dfrac{20^{10}-1}{20^{10}-3}=\dfrac{20^{10}-3}{20^{10}-3}+\dfrac{2}{20^{10}-3}=1+\dfrac{2}{20^{10}-3}\)
\(\dfrac{2}{20^{10}-1}>\dfrac{2}{20^{10}-3}\Leftrightarrow A>B\)
A=20 mủ 10 - 1 +12/(20 mủ 10 -1)=1+12/20 MỦ 10 -1
B=20 mủ 10 - 3 + 2 /(20 mủ 10 - 3)=1+2/20 mủ 10 - 3
Vì ... bạn tự làm nha.nhớ k đấy
A=\(\frac{20^{10}+1}{20^{10}-1}\)=\(\frac{\left(20^{10}-1\right)+2}{20^{10}-1}\)=\(\frac{20^{10}-1}{20^{10}-1}+\frac{2}{20^{10}-1}\)=\(1+\frac{2}{20^{10}-1}\)
B= \(\frac{20^{10}-1}{20^{10}-3}=\frac{\left(20^{10}-3\right)+2}{20^{10}-3}\)=\(\frac{20^{10}-3}{20^{10}-3}+\frac{2}{20^{10}-3}=1+\frac{2}{20^{10}-3}\)
Vì 2010-1 > 2010-3
=>\(\frac{2}{20^{10}-1}< \frac{2}{20^{10}-3}\)
=> \(1+\frac{2}{20^{10}-1}< 1+\frac{2}{20^{10}-3}\)
=> A < B
Vậy A < B
A = \(\frac{20^{10}+1}{20^{10}-1}=1\) B = \(\frac{20^{10}-1}{20^{10}-3}=1\)
Nên A = B
\(A=\frac{20^{10}+1}{20^{10}-1}=\frac{20^{10}-1+2}{20^{10}-1}=1+\frac{2}{20^{10}-1}\)
\(B=\frac{20^{10}-1}{20^{10}-3}=\frac{20^{10}-3+2}{20^{10}-3}=1+\frac{2}{20^{10}-3}\)
Vì \(\frac{2}{20^{10}-1}< \frac{2}{20^{10}-3}\Rightarrow1+\frac{2}{20^{10}-1}< 1+\frac{2}{20^{10}-3}\Rightarrow A< B\)
Ta có:
A=\(\frac{20^{10}}{20^{10}-1}+\frac{1}{20^{10}-1}\)
B=\(\frac{20^{10}}{20^{10}-3}-\frac{1}{20^{10}-3}\)
Vì 2010-1>2010-3 =>A>B
ta thấy B>1 nên B=\(\frac{20^{10}-1}{20^{10}-3}\)>\(\frac{20^{10}-1+2}{20^{100}-3+2}\)=\(\frac{20^{10}+1}{20^{10}-1}\)=A
vậy B>A
nếu ko hiểu thì tham khảo trong SBT lớp 6 bài so sánh PS ấy
Vì \(20^{10}-1>20^{10}-3\)
\(\Rightarrow B=\frac{20^{10}-1}{20^{10}-3}>\frac{20^{10}-1+2}{20^{10}-3+2}=\frac{20^{10}+1}{20^{10}-1}=A\)
vậy \(A< B\)
A=2010+1/2010-1=1+(2/2010-1)>1
B=2010-1/2010-3=1-(2/2010-3)<1
=> A>B
tick nha bạn
Ta có:
\(A=\frac{20^{10}+1}{20^{10}-1}=1\)
\(B=\frac{20^{10}-1}{20^{10}-3}=1\)
Vậy A và B bằng nhau
Tính A và B rồi ta so sánh:
A = \(\frac{20^{10}+1}{20^{10}-1}\) = \(1\)
B = \(\frac{20^{10}-1}{20^{10}-3}\) = \(1\)
Mà \(1\) = \(1\)
Nên: A = B
\(A=\frac{20^{10}+1}{20^{10}-1}=\frac{20^{10}-1}{20^{10}-1}+\frac{2}{20^{10}-1}=1+\frac{2}{20^{10}-1}\)
\(B=\frac{20^{10}-1}{20^{10}-3}=\frac{20^{10}-3}{20^{10}-3}+\frac{2}{20^{10}-3}=1+\frac{2}{20^{10}-3}\)
\(20^{10}-1>20^{10}-3\Rightarrow\frac{2}{20^{10}-1}< \frac{2}{20^{10}-3}\)
=> A < B