tìm x, biết : 3 mũ x + 4 +3 mũ x +2 = 270
K
Khách
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
Những câu hỏi liên quan
HQ
Hà Quang Minh
Giáo viên
19 tháng 7 2023
1) \(2^x=4^3 \Leftrightarrow2^x=2^6\Leftrightarrow x=6\)
2) \(2^x=4^6\Leftrightarrow2^x=2^{12}\Leftrightarrow x=12\)
3) \(3^x=9^{10}\Leftrightarrow3^x=3^{20}\Leftrightarrow x=20\)
NN
Nguyễn Ngọc Anh Minh
CTVHS
VIP
8 tháng 8 2023
a/
\(x^3-4x^2-\left(x-4\right)=0\)
\(\Leftrightarrow x^2\left(x-4\right)-\left(x-4\right)=0\)
\(\Leftrightarrow\left(x-4\right)\left(x^2-1\right)=0\)
\(\Leftrightarrow\left(x-4\right)\left(x-1\right)\left(x+1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-4=0\\x-1=0\\x+1=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=1\\x=-1\end{matrix}\right.\)
b/
\(x^5-9x=0\)
\(\Leftrightarrow x\left(x^4-9\right)=x\left(x^2-3\right)\left(x^2+3\right)=0\)
\(\Leftrightarrow x\left(x-\sqrt{3}\right)\left(x+\sqrt{3}\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\sqrt{3}\\x=-\sqrt{3}\end{matrix}\right.\)
c/
\(\left(x^3-x^2\right)^2-4x^2+8x-4=0\)
\(\Leftrightarrow x^4\left(x-1\right)^2-4\left(x-1\right)^2=0\)
\(\Leftrightarrow\left(x-1\right)^2\left(x^4-4\right)=0\)
\(\Leftrightarrow\left(x-1\right)^2\left(x^2-2\right)\left(x^2+2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\x^2-2=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\pm\sqrt{2}\end{matrix}\right.\)
LT
Lương Thị Vân Anh
CTVHS
16 tháng 7 2023
( 3x - 24 ) . 73 = 2 . 74
3x - 16 = 2 . 74 : 73 = 14
3x = 14 + 16 = 30
x = 10
16 tháng 7 2023
\(\left(3\times x-2^4\right)\times7^3=2\times7^4\)
\(\left(3\times x-2^4\right)\div2=7^4\div7^3\)
\(\left(3\times x-16\right)\div2=7\)
\(3\times x-16=7\times2\)
\(3\times x-16=14\)
\(3\times x=14+16\)
\(3\times x=30\)
\(x=30\div3\)
\(x=10\)
8 tháng 8 2023
a. x mũ 2 - 2x + 1 = 25
= x^2 + 2.x.1 + 1^2
= ( x + 1 ) ^2
ko bt có đúng ko nữa, mấy câu kia tui ko bt lm
14 tháng 10 2018
Bo may la binh day k di hieu ashdbfgbgygygggydfsghuyfhdguuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu3
\(3^{x+4}+3^{x+2}=270\)
\(3^{x+2+2}+3^{x+2}=270\)
\(3^{x+2}\cdot3^2+3^{x+2}\cdot1=270\)
\(3^{x+2}\left(3^2+1\right)=270\)
\(3^{x+2}\cdot10=270\)
\(3^{x+2}=270:10\)
\(3^{x+2}=27\)
\(3^{x+2}=3^3\)
\(x+2=3\)
\(x=1\)
Bài giải
\(3^{x+4}+3^{x+2}=270\)
\(3^{x+2}\left(3^2+1\right)=270\)
\(3^{x+2}\cdot10=270\)
\(3^{x+2}=27=3^3\)
\(x+2=3\)
\(x=1\)