Sửa đề: \(C=1+3^1+3^2+...+3^{100}\)

b) Ta có: \(C=1+3^1+3^2+...+3^{100}\)

\(\Leftrightarrow3\cdot C=3+3^2+...+3^{101}\)

\(\Leftrightarrow C-3\cdot C=1+3+3^2+...+3^{100}-3-3^2-...-3^{100}-3^{101}\)

\(\Leftrightarrow-2\cdot C=1-3^{101}\)

hay \(C=\dfrac{3^{101}-1}{2}\)

b) Ta có: C=1+31+32+...+3100C=1+31+32+...+3100

⇔3⋅C=3+32+...+3101⇔3⋅C=3+32+...+3101

⇔C−3⋅C=1+3+32+...+3100−3−32−...−3100−3101⇔C−3⋅C=1+3+32+...+3100−3−32−...−3100−3101

⇔−2⋅C=1−3101

\(=\dfrac{2^{10}.\left(13+65\right)}{2^8.104}=\dfrac{2^{10}.78}{2^8.104}=\dfrac{2^2.78}{104}=\dfrac{78}{26}=3\)

\(A=\dfrac{3^{10}\cdot11+3^{10}\cdot5}{3^9\cdot2^4}=\dfrac{3^{10}\cdot\left(11+5\right)}{3^9\cdot16}=\dfrac{3^{10}\cdot16}{3^9\cdot16}=3\)

\(B=\dfrac{2^{10}\cdot13+2^{10}\cdot65}{2^8\cdot104}=\dfrac{2^{10}\cdot\left(13+65\right)}{2^8\cdot2^2\cdot26}=\dfrac{2^{10}\cdot78}{2^{10}\cdot26}=3\)

\(C=\dfrac{72^3\cdot54^2}{108^4}=\dfrac{\left(2^3\cdot3^2\right)^3\cdot\left(2\cdot3^3\right)^2}{\left(3^3\cdot2^2\right)^4}\\ =\dfrac{2^9\cdot3^6\cdot2^4\cdot3^6}{3^{12}\cdot2^8}=\dfrac{2^{13}\cdot3^{12}}{3^{12}\cdot2^8}=2^5=32\)

\(D=\dfrac{11\cdot3^{22}\cdot3^7-9^{15}}{\left(2\cdot3^{14}\right)^2}=\dfrac{11\cdot3^{29}-\left(3^2\right)^{15}}{2^2\cdot3^{28}}=\dfrac{11\cdot3^{29}-3^{30}}{2^2\cdot3^{28}}\\ =\dfrac{3^{29}\cdot\left(11-3\right)}{2^2\cdot3^{28}}=\dfrac{3^{29}\cdot8}{4\cdot3^{28}}=3\cdot2=6\)

a, \(B=\dfrac{2^{10}.13+2^{10}.65}{2^8.104}\)

\(=\dfrac{2^{10}.\left(13+65\right)}{2^8.2^3.13}\)

\(=\dfrac{2^{10}.78}{2^{11}.13}\)\(=\dfrac{1.6}{2.1}=\dfrac{1.3}{1.1}=3\)

b: \(=\dfrac{2^{20}\cdot3^2+2^{54}}{2^{18}\cdot5^2}=\dfrac{2^{20}\left(3^2+2^{32}\right)}{2^{18}\cdot5^2}=\dfrac{2^2\left(3^2+2^{32}\right)}{25}\)

c: \(=\dfrac{2^9\cdot3^6\cdot3^6\cdot2^2}{2^8\cdot3^{12}}=\dfrac{2^{11}}{2^8}=8\)

d: \(=\dfrac{2^{12}\cdot3^4\cdot3^{10}}{2^{12}\cdot3^{12}}=9\)

\(\frac{2^{10}.13+2^{10}.65}{2^8.104}\)

Xét : 210 . 13 + 210. 65 = 210 . ( 13 + 65 ) = 210 . 78 

         2⁸  . 104 = 2⁸ . ( 2² . 26 ) = 2⁸. 2². 26 = 2¹⁰.26

có : \(\frac{2^{10}.13+2^{10}.65}{2^8.104}\)= \(\frac{2^{10}.78}{2^{10}.26}\)= \(\frac{78}{26}\)= 3

\(\frac{2^{10}.13+2^{10}.65}{2^8.104}=\frac{2^{10}.\left(13+65\right)}{2^8.104}=\frac{2^{10}.78}{2^8.104}\)

\(=\frac{2^2.39}{52}=\frac{2^2.39}{2^2.13}\)

\(=\frac{39}{13}\)

\(=3\)

2¹⁰.13+2¹⁰.65 = 2¹⁰(13 + 65) = 2¹⁰ . 78 = 1024 . 78 = 79872

2^8.104 = 2⁸³²

2¹⁰.13+2¹⁰.65= (13 + 65 ) . 2¹⁰

                    =  78 . 2¹⁰

                           = 78 . 1024

                     =  79872

 2^8.104= 2¹¹²

\(\frac{2^{10}.13+2^{10}.65}{2^{8^{ }}.104}=\frac{2^{10}\left(13+65\right)}{2^8.104}=\frac{2^8.2^2.78}{2^8.104}=3\)

\(\frac{2^{10}.13+2^{10}.65}{2^8.104}=\frac{2^{10}\left(13+65\right)}{2^8.104}=\frac{2^8.2^2.78}{2^8.104}=3\)

\(\frac{2^{10}.13+2^{10}.65}{2^8.104}\)

\(=\frac{2^{10}.\left(13+65\right)}{2^8.104}\)

\(=\frac{2^{10}.78}{2^8.104}\)

\(=\frac{2^8.2^2.78}{2^8.104}\)

\(=\frac{2^8.4.78}{2^8.104}\)

\(=\frac{2^8.312}{2^8.104}\)

\(=\frac{2^8.3.104}{2^8.104}=3\)