Không quy đôngf mẫu số hãy so sánh
A= -9/ 10 ^2010 + -19/ 10^2011
B= -9/ 10^2011 + -19/ 10^2010
A= -9/10^2010 + (-19/10^2011) B= -9/10^2011 + (-19/10^2010) Không quy đồng mẫu số hãy so sánh
\(A=\dfrac{-9\cdot10+\left(-19\right)}{10^{2011}}=\dfrac{-28}{10^{2011}}\)
\(B=\dfrac{-9\cdot10-19}{10^{2011}}=\dfrac{-109}{10^{2011}}\)
=>A>B
KHÔNG QUY ĐỒNG MẪU SỐ HÃY SO SÁNH: A=-9/10^2010+-19/10^2011; B=-9/10^2011+-19/10^2010
KHÔNG QUY ĐỒNG MẪU SỐ HÃY SO SÁNH:A=-9/10^2010+-19/10^2011; B=-9/10^2011+-19/10^2010
Không quy đồng mẫu hãy so sánh
A=-9/102010+-19/102011; B=-9/102011+-19/102010
Không quy đồng mẫu số hãy so sánh:
A=-9/102010+-19/102011; B=-9/102011+-19/102010
\(A=-\frac{9}{10^{2010}}-\frac{19}{10^{2011}}=-\frac{9}{10^{2010}}-\frac{10}{10^{2010}}+\frac{10}{10^{2010}}-\frac{9}{10^{2011}}-\frac{10}{10^{2011}}.\)
\(=-\frac{19}{10^{2010}}-\frac{9}{10^{2011}}+\frac{1}{10^{2009}}-\frac{1}{10^{2010}}=B+\frac{1}{10^{2009}}-\frac{1}{10^{2010}}\)
\(\Rightarrow A-B=\frac{1}{10^{2009}}-\frac{1}{10^{2010}}>0\Rightarrow A>B.\)
\(-A=\frac{9}{10^{2010}}+\frac{19}{10^{2011}}\)
\(-A=\frac{9}{10^{2010}}+\frac{10}{10^{2011}}+\frac{9}{10^{2011}}\)
\(-A=\frac{9}{10^{2010}}+\frac{1}{10^{2010}}+\frac{9}{10^{2011}}\)
\(-A=\frac{10}{10^{2010}}+\frac{9}{10^{2011}}\)
\(-A=\frac{1}{10^{2009}}+\frac{9}{10^{2011}}\)
Tương tự với B, ta có:
\(-B=\frac{9}{10^{2011}}+\frac{19}{10^{2010}}\)
\(-B=\frac{9}{10^{2011}}+\frac{10}{10^{2010}}+\frac{9}{10^{2010}}\)
\(-B=\frac{9}{10^{2010}}+\frac{1}{10^{2009}}+\frac{9}{10^{2010}}\)
Ta thấy -B > -A \(\Rightarrow\)A > B.
A=\(\frac{-9}{10^{2011}^{ }}\)+\(\frac{-19}{10^{2011}}\)=\(\frac{-9}{10^{2010}}\)+\(\frac{-9}{10^{2011}}\)+\(\frac{-10}{2011}\)
B=\(\frac{-9}{10^{2011}}\)+\(\frac{-19}{10^{2010}}\)=\(\frac{-9}{10^{2011}}\)+\(\frac{-9}{10^{2010}}\)+\(\frac{-10}{2010}\) \(\frac{-10}{2011}\)>\(\frac{-10}{2010}\)vậy A>Bkhông quy đồng mẫu số hãy so sánh:
A= \(\frac{-9}{10^{2010}}+\frac{-19}{10^{2011}}\) với B= \(\frac{-9}{10^{2011}}+\frac{-19}{10^{2010}}\)
−9102010 +−19102011 = −9102011 +−19102010
Không quy đồng mẫu số hãy so sánh :
\(A=\frac{-9}{10^{2010}}+\frac{-19}{10^{2011}}\)
\(B=\frac{-9}{10^{2011}}+\frac{-19}{10^{2010}}\)
Không quy đồng mẫu số hãy so sánh \(A=\frac{-9}{10^{2010}}+\frac{-19}{10^{2011}}\)\(;B=\frac{-9}{10^{2011}}+\frac{-19}{10^{2010}}\)
\(A-B=\frac{10}{10^{2010}}-\frac{10}{10^{2011}}=\frac{1}{10^{2009}}-\frac{1}{10^{2010}}>0\)
\(\Rightarrow A>B\)
+)Ta có:A=\(\frac{-9}{10^{2010}}+\frac{-19}{10^{2011}}=\frac{-9}{10^{2010}}+\frac{-9}{10^{2011}}+\frac{-10}{10^{2011}}\)
+)Ta lại có:B=\(\frac{-9}{10^{2011}}+\frac{-19}{10^{2010}}=\frac{-9}{10^{2011}}+\frac{-9}{10^{2010}}+\frac{-10}{10^{2010}}\)
+)Ta thấy:\(\frac{-10}{10^{2011}}>\frac{-10}{10^{2010}}\)
=>\(\frac{-9}{10^{2010}}+\frac{-9}{10^{2011}}+\frac{-10}{10^{2011}}\)>\(\frac{-9}{10^{2011}}+\frac{-9}{10^{2010}}+\frac{-10}{10^{2010}}\)
Hay A>B
Vậy A>B
Chúc bn học tốt
Không quy đồng mẫu số hãy so sánh
A = -9 / 10^2011 + -19 / 10^2011
B = -9 / 10^2011 + -19 / 10^2010
\(A=-\frac{9}{10^{2011}}+\left(-\frac{19}{10^{2011}}\right)\)
\(B=-\frac{9}{10^{2011}}+\left(-\frac{19}{10^{2010}}\right)\)
Do \(-\frac{9}{10^{2011}}=-\frac{9}{10^{2011}}\)VÀ \(-\frac{19}{10^{2011}}< -\frac{19}{10^{2010}}\)
\(\Rightarrow-\frac{9}{10^{2011}}+\left(-\frac{19}{10^{2011}}\right)>-\frac{9}{10^{2011}}+\left(-\frac{19}{10^{2010}}\right)\)
\(\Leftrightarrow A>B\)