Tìm x biết:
2x+2x+1=24
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1: =>\(5^{x-2}-9=2^4-\left(6^2-6^2\right)\)
=>\(5^{x-2}=16+9=25\)
=>x-2=2
=>x=4
2: \(\Leftrightarrow3^x+16=19^6:19^5-3=19-3=16\)
=>3^x=0
=>x=0
3: \(\Leftrightarrow2^x+2^x\cdot16=272\)
=>2^x*17=272
=>2^x=16
=>x=4
4: \(\Leftrightarrow2^{x-1}+3=24-\left(4^2-2^2+1\right)=24-\left(16-4+1\right)\)
=>\(2^{x-1}+3=24-16+4-1=8+4-1=12-1=11\)
=>2^x-1=8
=>x-1=3
=>x=4
`1/3 : (2x - 1) = (-4/24)`
`2x - 1 = 1/3 : (-4/24)`
`2x - 1 = -2`
`2x = (-2) + 1`
`2x = (-1)`
`x = 2 : (-1)`
`x = -2`
\(5x\left(x-2\right)-3\left(x-1\right)=20x^2-15x\left(2x+1\right)-24\)
\(\Rightarrow5x^2-10x-3x+3=20x^2-30x^2-15x-24\)
\(\Rightarrow5x^2-13x+3=-10x^2-15x-24\)
\(\Rightarrow5x^2+10x^2-13x+15x+3+24=0\)
\(\Rightarrow15x^2+2x+27=0\)
Ta có:
\(\Delta=2^2-4\cdot15\cdot27==-1616< 0\)
Nên pt vô nghiệm
\(5x\left(x-2\right)-3\left(x-1\right)=20x^2-15x\left(2x+1\right)-24\\ \Leftrightarrow5x^2-10x-3x+3=20x^2-30x^2-15x-24\\ \Leftrightarrow5x^2-20x^2+30x^2-10x-3x+15x+3+24=0\\ \Leftrightarrow15x^2+2x+27=0\\ \Leftrightarrow15x^2-2.x.\sqrt{15}+\dfrac{2}{15}+\dfrac{403}{15}=0\\ \Leftrightarrow\left(\sqrt{15}x+\dfrac{\sqrt{30}}{15}\right)^2+\dfrac{403}{15}=0\left(Vô.lí\right)\\ Vậy:Không.có.x.thoả\)
a: \(x^3=27\)
=>\(x^3=3^3\)
=>x=3
b: \(\left(2x-1\right)^3=8\)
=>\(\left(2x-1\right)^3=2^3\)
=>2x-1=2
=>2x=2+1=3
=>\(x=\frac32=1,5\)
c: \(\left(x-2\right)^2=16\)
=>\(\left[\begin{array}{l}x-2=4\\ x-2=-4\end{array}\right.\Rightarrow\left[\begin{array}{l}x=4+2=6\\ x=-4+2=-2\end{array}\right.\)
d: \(\left(2x-3\right)^2=9\)
=>\(\left[\begin{array}{l}2x-3=3\\ 2x-3=-3\end{array}\right.\Longrightarrow\left[\begin{array}{l}2x=6\\ 2x=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=3\\ x=0\end{array}\right.\)
e: \(2x+5=3^4:3^2\)
=>\(2x+5=3^2=9\)
=>2x=9-5=4
=>\(x=\frac42=2\)
f: \(\left(3x-2^4\right)\cdot7^3=2\cdot7^4\)
=>\(3x-16=2\cdot\frac{7^4}{7^3}=2\cdot7=14\)
=>3x=16+14=30
=>\(x=\frac{30}{3}=10\)
a: \(x^3=27\)
=>\(x^3=3^3\)
=>x=3
b: \(\left(2x-1\right)^3=8\)
=>\(\left(2x-1\right)^3=2^3\)
=>2x-1=2
=>2x=2+1=3
=>\(x=\frac32=1,5\)
c: \(\left(x-2\right)^2=16\)
=>\(\left[\begin{array}{l}x-2=4\\ x-2=-4\end{array}\right.\Rightarrow\left[\begin{array}{l}x=4+2=6\\ x=-4+2=-2\end{array}\right.\)
d: \(\left(2x-3\right)^2=9\)
=>\(\left[\begin{array}{l}2x-3=3\\ 2x-3=-3\end{array}\right.\Longrightarrow\left[\begin{array}{l}2x=6\\ 2x=0\end{array}\right.\Rightarrow\left[\begin{array}{l}x=3\\ x=0\end{array}\right.\)
e: \(2x+5=3^4:3^2\)
=>\(2x+5=3^2=9\)
=>2x=9-5=4
=>\(x=\frac42=2\)
f: \(\left(3x-2^4\right)\cdot7^3=2\cdot7^4\)
=>\(3x-16=2\cdot\frac{7^4}{7^3}=2\cdot7=14\)
=>3x=16+14=30
=>\(x=\frac{30}{3}=10\)
x^2 -2x = 24
=> x^2 - 2x - 24=0
=>x^2 -8x+6x - 24 = 0
=> ( x^2- 8x)+( 6x-24) = 0
=> x(x-8) + 6(x-8) = 0
=> (x+6)(x-8)=0
=>\(\orbr{\begin{cases}x=-6\\x=8\end{cases}}\)
2x + 2x + 1 = 24
2x.(1 + 2) = 24
2x = 8 = 23
=> x = 3