(2x-3)2 =81
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a: =>1/3:x=3/5-2/3=9/15-10/15=-1/15
=>x=-1/3:1/15=5
b: \(\Leftrightarrow x\cdot\dfrac{2}{3}-3=\dfrac{2}{5}\cdot\left(-10\right)=-4\)
=>x*2/3=-1
=>x=-3/2
c: =>2x+1=4 hoặc 2x+1=-4
=>x=3/2 hoặc x=-5/2
h: =>x-3=4
=>x=7
g: =>2x-1=3
=>2x=4
=>x=2
f: \(\Leftrightarrow x\cdot\left(\dfrac{3}{2}-\dfrac{7}{3}\right)=\dfrac{3}{2}-\dfrac{2}{3}\)
=>x*-5/6=5/6
=>x=-1
d: =>|2x-1|=3
=>2x-1=3 hoặc 2x-1=-3
=>x=-1 hoặc x=2
\(\left(2x-\dfrac{3}{2}\right)^2=\dfrac{49}{81}\\ \Rightarrow\left(2x-\dfrac{3}{2}\right)^2=\left(\dfrac{7}{9}\right)^2\\ \Rightarrow2x-\dfrac{3}{2}=\pm\dfrac{7}{9}\\ \Rightarrow\left[{}\begin{matrix}2x-\dfrac{3}{2}=\dfrac{7}{9}\\2x-\dfrac{3}{2}=-\dfrac{7}{9}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}2x=\dfrac{41}{18}\\2x=\dfrac{13}{18}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{41}{36}\\x=\dfrac{13}{36}\end{matrix}\right.\)
(2x-3/2)2=49/81=(7/9)2
=>2x-3/2=7/9 hoặc 2x-3/2=-7/9
=>x=41/36 hoặc x=13/36.
\(3^{2x}=81^2\)
\(3^{2x}=(3^4)\)
\(3^{2x}=3^8\)
\(2x=8\)
\(x=8\div2\)
\(x=4\)
a)5^x=125
125=5^3
5^x=5^3
=>x=3
b)3^2x=81
81=3^4
3^2x=3^4
=>2x=4
x=4:2
x=2
3
\(4.\left(3-2x\right)^2=\frac{1}{81}\)
\(\left(3-2x\right)^2=\frac{1}{324}\)
\(\Leftrightarrow\orbr{\begin{cases}3-2x=\frac{1}{18}\\3-2x=\frac{-1}{18}\end{cases}\Leftrightarrow\orbr{\begin{cases}x=\frac{53}{36}\\x=\frac{55}{36}\end{cases}}}\)
Vậy \(x\in\left\{\frac{53}{36};\frac{55}{36}\right\}\)
a) 3^2x=9^2
3^2x=3^2.3^2
3^2x=3^4
3^2x=3^2.2
=>2x=2.2
=>x=4/2
=>x=2
a, 2x-1 = 64
=> 2x-1 = 26
=> x - 1 = 6
=> x = 6 + 1
=> x = 7
b, 32x-10 = 81
=> 32x-10 = 34
=> 2x - 10 = 4
=> 2x = 14
=> x = 7
c, 22x+3 = 1024
=> 22x+3 = 210
=> 2x + 3 = 10
=> 2x = 7
=> x = \(\frac{7}{2}\)
`@` `\text {Ans}`
`\downarrow`
`(2x - 3)^2 = 81`
`=> (2x - 3)^2 = (+-9)^2`
`=>`\(\left[{}\begin{matrix}2x-3=9\\2x-3=-9\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}2x=12\\2x=-6\end{matrix}\right.\)
`=>`\(\left[{}\begin{matrix}x=6\\x=-3\end{matrix}\right.\)
Vậy, `x \in `\(\left\{-3;6\right\}\)
\(\left(2x-3\right)^2=81=9^2\Rightarrow2x-3=9\Rightarrow2x=12\Rightarrow x=6\)