Question

Answer 1

a) \(\Leftrightarrow\left[{}\begin{matrix}x=55\\x=22\end{matrix}\right.\)

b) \(\Leftrightarrow x^2=9\\ \Leftrightarrow\left[{}\begin{matrix}x=-3\\x=3\end{matrix}\right.\)

c) \(\Leftrightarrow\left(x+1\right)^3=8\\ \Leftrightarrow x+1=2\\ \Leftrightarrow x=1\)

d) \(\Leftrightarrow5\left(x-2\right)^2=125\\ \Rightarrow\left(x-2\right)^2=25\\ \Leftrightarrow\left[{}\begin{matrix}x-2=-5\\x-2=5\end{matrix}\right.\\ \Leftrightarrow\left[{}\begin{matrix}x=-3\\x=7\end{matrix}\right.\)

Answer 2

g) => 55-x=0 hoặc 2x-44=0
    =>x=55 hoặc x=22
h) x²=9
=>x=-3 hoặc x=3
i) =>(x+1)³=8
=>x+1=2
x=1
j)5(x-2)²=125
(x-2)²=25
=>x-2=5 hoặc x-2=-5
=>x=7 hoặc x=-3

Answer 3