a) A=\(\frac{178}{179}+\frac{179}{180}+\frac{183}{181}\)
ta có :
\(A=\left(1-\frac{1}{179}\right)+\left(1-\frac{1}{180}\right)+\left(1+\frac{2}{181}\right)\)
\(\Rightarrow A=\left(1+1+1\right)-\left(\frac{1}{179}-\frac{1}{180}+\frac{2}{181}\right)\)
\(\Rightarrow A=3-\left(\frac{1}{179}-\frac{1}{180}+\frac{2}{181}\right)< 3\)
Vậy \(A< 3\)
a. Ta có :
\(\frac{178}{179}< 1\left(\frac{1}{179}\right)\)
\(\frac{179}{180}< 1\left(\frac{1}{180}\right)\)
\(\frac{183}{181}>1\left(\frac{3}{181}\right)\left(1\right)\)
Mà \(\frac{3}{181}>\frac{1}{179}+\frac{1}{180}\left(=\frac{359}{32220}< \frac{3}{181}\right)\left(2\right)\)
Từ \(\left(1\right)\&\left(2\right)\Rightarrow\frac{178}{179}+\frac{179}{180}+\frac{183}{181}< 1+1+1\)
Vậy \(A< 3\)
b) \(A=\frac{1+5+5^2+5^3+...+5^{10}+5^{11}}{1+5+5^2+5^3+...+5^9+5^{10}}=5^{11}\)
bn rút gọn là dc
\(B=\frac{1+7+7^2+7^3+...+7^{10}+7^{11}}{1+7+7^2+7^3+...+7^9+7^{10}}=7^{11}\)
\(A=5^{11},B=7^{11}\)
\(\Rightarrow7^{11}>5^{11}\Rightarrow B>A\)
hk tốt #
bn Rim Cell làm sai rùi kìa :
sao \(\frac{178}{179}< 1\left(\frac{1}{179}\right)\)rõ ràng là \(\frac{178}{179}phải>1\left(\frac{1}{179}\right)=\frac{1}{179}\)
bn làm sai rùi kết quả thì đúng !
a) \(A=\frac{178}{179}+\frac{179}{180}+\frac{183}{181}\)
\(\Rightarrow A=\left(1-\frac{1}{179}\right)+\left(1-\frac{1}{180}\right)+\left(1+\frac{1}{181}\right)\)
\(\Rightarrow A=\left(1+1+1\right)-\left(\frac{1}{179}-\frac{1}{180}+\frac{1}{181}\right)\)
\(\Rightarrow3-\left(\frac{1}{179}-\frac{1}{180}+\frac{1}{181}\right)< 3\)
\(\Rightarrow A< 3\)
hk tốt #
Bạn ๖ACE✪ɪ➻❥ʟᴏᴠᴇ➻❥ᴋᴀʀᴀᴛe-ᴅᴏ✌ k hiểu ý mk rồi
\(\frac{178}{179}< 1\left(\frac{1}{179}\right)\)ý là mk trích ra từ 1 - 178/179 để suy ra đoạn cuối đó bạn
-.-
ak hóa ra là thế,sorry ,mk đền cho 3 k
