tìm n biết:
\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2^n\)
Tìm n là số tự nhiên, biết:
a)\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}+\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2^n\)
b) 2.2n + 3.23 + 4.24 + ...+ n.2n = 2n + 10
a)
4^5+4^5+4^5+4^5/3^5+3^5+3^5 =4^5.4/3^5.3
=4^6/3^6
tương tự ta có phân số còn lại là
6^5.6/=2^5.2
=6^6/2^6
ta có 4^6/3^6+6^6/2^6 ta rút gọn 4^6 với 2^6 và 6^6 với 3^6 được 2/1+2/1=2^2
suy ra số đó là 2
tìm số nguyên dương n biết:\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2^n\)
\(=\frac{4\cdot4^5}{3\cdot3^5}\cdot\frac{6\cdot6^5}{2\cdot2^5}=\frac{4^6}{3^6}\cdot\frac{6^6}{2^6}=\frac{2^{12}\cdot2^6\cdot3^6}{3^6\cdot2^6}=2^{12}=2^n\Rightarrow n=12\)
Tìm x biết:
a.
\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}.\frac{4}{10}.\frac{5}{12}...\frac{30}{62}.\frac{31}{64}=2^x\)
b.
\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2^x\)
\(\frac{1}{4}\cdot\frac{2}{6}\cdot\frac{3}{8}\cdot\frac{4}{10}\cdot....\cdot\frac{30}{62}\cdot\frac{31}{64}=2^x\)
\(\Leftrightarrow\frac{1}{2}\left(\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot.....\cdot\frac{30}{31}\cdot\frac{31}{32}\right)=2^x\)
\(\Leftrightarrow\frac{1}{32}=2^{x+1}\)
Làm nốt.
ko làm được câu này hay câu b ib với tớ nha.khẳng định tối giải.
A)\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}.\frac{4}{10}.\frac{5}{12}....\frac{30}{62}.\frac{31}{64}=4^x\)
B)\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=8^x\)
Tìm số nguyên dương n thỏa mãn:
\(\dfrac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\dfrac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2n\)
Help me please!!!!!
Câu hỏi của Lê Khánh Nhi - Toán lớp 7 - Học toán với OnlineMath sửa n thành x cho sửa cho nó thành lũy thừa luôn
Tính P = 1 + \(\frac{1}{2}\)(1 + 2) + \(\frac{1}{3}\)(1 + 2 + 3) + \(\frac{1}{4}\)(1 + 2 + 3 + 4) +.....+\(\frac{1}{2019}\)(1 + 2 + 3+.....+ 2019)
2 Tìm x Thỏa mãn
\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}\cdot\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2^x\)
GIÚP MÌNH VỚI!!!!!
\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}\)*\(\frac{6^5+6^5+^{_{6^5}}+6^5+6^5+6^5}{2^5+2^5}\)=\(^{2^x}\)
Tìm x biết
\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}\cdot\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=8^{\left|2x+6\right|}\)
\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=8^{\left|2x+6\right|}\)
\(\Leftrightarrow\frac{4.\left(4^5\right)}{3.\left(3^5\right)}.\frac{6.\left(6^5\right)}{2.\left(2^5\right)}=8^{\left|2x+6\right|}\)
\(\Leftrightarrow\frac{4^6.6^6}{3^6.2^3}=8^{\left|2x+6\right|}\)
\(\Leftrightarrow\frac{\left(2^2\right)^6.\left(2.3\right)^6}{3^6.2^3}=8^{\left|2x+6\right|}\)
\(\frac{2^{12}.2^6.3^6}{3^6.2^3}=\frac{2^{18}.3^6}{3^6.2^3}=\frac{2^{15}.1}{1.1}=2^{15}=8^{\left|2x+6\right|}\)
=> 215=(23)|2x+6|
215=23|2x+6|
<=> 3|2x+6|=15
|2x+6|=15:3
|2x+6|=5
\(\Rightarrow\orbr{\begin{cases}2x+6=5\\2x+6=-5\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{-1}{2}\\x=\frac{-11}{2}\end{cases}}\)
Tìm x biết: \(\frac{4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=8^x\)
\(\frac{4^5+4^5+4^5}{3^5+3^5+3^5}\cdot\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=8^x\)
\(\Rightarrow\frac{3\cdot2^{10}}{3^6}\cdot\frac{6^6}{2^6}=8^x\)
\(\Rightarrow\frac{4^5}{3^5}\cdot3^6=8^x\)
\(\Rightarrow4^5\cdot3=8^x\)
hình như sai đề hoặc mik làm sai:))
\(\frac{4^5+4^5+4^5}{3^5+3^5+3^5}\cdot\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=8^x\)
\(\frac{3\cdot4^5}{3\cdot3^5}\cdot\frac{6\cdot6^5}{2\cdot2^5}=8^x\)
\(\frac{4^5}{3^5}\cdot\frac{6^6}{2^5}=8^x\)
\(\left(\frac{4}{3}\right)^5\cdot\left(\frac{6}{2}\right)^6=8^x\)
\(\frac{4^5}{3^5}\cdot3^6=8^x\)
\(4^5\cdot3=8^x\)
\(1024\cdot3=8^x\)
\(3072=8^x\)
\(\Rightarrow\text{ }x\in\varnothing\)