a)10x.4=400 b)x20=x
10x=400/4 x=1
10x=100 d)(x-2)5=(x-2)3
x=2 x=2
c)(2x+1)2=121
2x+1=11
2x=11-1
2x=10
x=10/2
x=5
Bài 1 : a ) \(10^x.4=400\)
\(\Leftrightarrow10^x=400:4\)
\(\Leftrightarrow10^x=100\)
\(\Leftrightarrow10^x=10^2\)
\(\Leftrightarrow x=2\)
b ) \(x^{20}=x\)
\(\Rightarrow x=1\)
c ) \(\left(2x+1\right)^2=121\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}2x+1=11\\2x+1=-11\end{array}\right.\)
\(\Leftrightarrow\left[\begin{array}{nghiempt}2x=120\\2x=-122\end{array}\right.\Leftrightarrow\left[\begin{array}{nghiempt}x=60\\x=-61\end{array}\right.\)
Vậy ...........................
d ) \(\left(x-2\right)^5=\left(x-\right)^3\) ( Để sao vậy bạn )
