a) \(\sqrt{x}+5=10\) (1)
ĐKXĐ: \(x\ge0\)
(1) \(\Leftrightarrow\) \(\sqrt{x}=10-5\)
\(\sqrt{x}=5\)
\(x=25\) (nhận)
Vậy x = 25
b) \(\sqrt{2x}=6\) (2)
ĐKXĐ: \(x\ge0\)
(2) \(\Leftrightarrow2x=36\)
\(x=\frac{36}{2}\)
\(x=18\) (nhận)
Vậy x = 18
c) \(\sqrt{\left(3x-1\right)^2}=5\) (3)
ĐKXĐ: Với mọi \(x\in R\)
(3) \(\Leftrightarrow\left|3x-1\right|=5\)
\(\Rightarrow3x-1=5\) hoặc \(3x-1=-5\)
*) \(3x-1=5\)
\(\text{3x = 5 + 1}\)
\(\text{3x = 6}\)
\(x=\frac{6}{3}\)
\(x=2\)
*) \(3x-1=-5\)
\(3x=-5+1\)
\(3x=-4\)
\(x=\frac{-4}{3}\)
Vậy \(x=2\); \(x=\frac{-4}{3}\)
