a) ( x+1)2 =25
Ta có :
52=25
=> ( x+1)2)=52
=> x+1=5
=> x=4
b) 32x=210
=> 32x=(22.5)
=> 32x=(25)2
=> 32x=322
=> x=2
c) 9x=81
Ta có :
92=81
=> 9x=92
=> x=2
d) 3. (2x +1)2=48
=> (2x +1)2=42:3
=> (2x +1)2=16
Mà :
42=16
=> (2x +1)2=42
=> 2x+1=4
=> 2x=3
=> x=1,5
e) (x-1)4 = (x-1)2
TH1: (x-1)4 = (x-1)2=0
=> x=1
TH2: (x-1)4 = (x-1)2=1
=> x=2
Xong :)
a) \(\left(x+1\right)^2=25\)
\(\left(x+1\right)^2=5^2=\left(-5\right)^2\)
Nếu \(x+1=5\)\(\Rightarrow x=5-1=4\)
Nếu \(x+1=-5\)\(x=\left(-5\right)-1=-6\)
a)\(\left(x+1\right)^2\)=25<=>\(\sqrt{\left(x+1\right)^2}\)=\(\sqrt{25}\)(1)
*TH1: x>=1 =>(1)<=>x+1=5<=>x=4(Thỏa mãn)
*TH2: x<1=>(1)<=>-(x+1)=5<=>-x-1=5<=>-x=6<=>x=-6(Thỏa mãn)
Vậy x=4 hoặc x=-6
b)32^x=2^10<=>(2^5)^x=2^10<=>2^5x+2^10<=>5x=10<=>x=2
c)9^x=81<=>9^x=9^2<=>x=2
d)3(2x+1)^2=48<=>(2x+1)^2=16<=>2x+1=4<=>x=1.5
e)(x-1)^4=(x-1)^2<=>x-1=0<=>x=1
a)(x+1)2=25 b)32x =210
(x+1)2=52 210=1024 =>x=32
x+1=5 c)9x=81
x=5-1 9x9=81 =>x=8
x=4
mk làm đc = zậy thui.sorry
a) (x+1)2=25
=> (x+1)2=52
\(\Rightarrow\orbr{\begin{cases}\left(x+1\right)^2=5^2\\\left(x+1\right)^2=\left(-5\right)^2\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x+1=5\\x+1=\left(-5\right)\end{cases}}\Rightarrow\orbr{\begin{cases}x=4\\x=\left(-6\right)\end{cases}}\)
b) 32x=210
=> (25)x=210
=> 25x=210
=> 5x=10
=> x=2
c) 9x=81
\(\Rightarrow9^x=\left(-9\right)^2\)
=> x=2
d) 3(2x+1)2=48
=> (2x+1)2=48:3
=> (2x+1)2=16
\(\Rightarrow\orbr{\begin{cases}\left(2x+1\right)^2=4^2\\\left(2x+1\right)^2=\left(-4\right)^2\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}2x+1=4\\2x+1=\left(-4\right)\end{cases}}\Rightarrow\orbr{\begin{cases}2x=3\\2x=\left(-5\right)\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=1,5\\x=-2,5\end{cases}}\)
e) (x-1)4=(x-1)2
\(\Rightarrow\left(x-1\right)^4:\left(x-1\right)^2=1\)
\(\Rightarrow\left(x-1\right)^2=1\)
\(\Rightarrow\orbr{\begin{cases}\left(x-1\right)^2=1^2\\\left(x-1\right)^2=\left(-1\right)^2\end{cases}}\Rightarrow\orbr{\begin{cases}x-1=1\\x-1=\left(-1\right)\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=2\\x=0\end{cases}}\)
a) ( x+1)2 =25
Ta có :
52=25
=> ( x+1)2)=52
=> x+1=5
=> x=4
b) 32x=210
=> 32x=(22.5)
=> 32x=(25)2
=> 32x=322
=> x=2
c) 9x=81
Ta có :
92=81
=> 9x=92
=> x=2
d) 3. (2x +1)2=48
=> (2x +1)2=42:3
=> (2x +1)2=16
Mà :
42=16
=> (2x +1)2=42
=> 2x+1=4
=> 2x=3
=> x=1,5
e) (x-1)4 = (x-1)2
TH1: (x-1)4 = (x-1)2=0
=> x=1
TH2: (x-1)4 = (x-1)2=1
=> x=2
Xong :)
