Question

Answer 1

b: ĐKXĐ: x>=0

\(3\sqrt{x}+1=40\)

=>\(3\sqrt{x}=40-1=39\)

=>\(\sqrt{x}=13\)

=>x=169(nhận)

c: ĐKXĐ: x-1>=0

=>x>=1

\(\sqrt{x-1}=9\)

=>\(x-1=9^2=81\)

=>x=81+1

=>x=82(nhận)

d: ĐKXĐ: x>=1/2

\(2\sqrt{2x-1}=6\)

=>\(\sqrt{2x-1}=3\)

=>2x-1=9

=>2x=10

=>x=5(nhận)

e: \(\sqrt{\left(x-3\right)^2}=3\)

=>|x-3|=3

=>\(\left[\begin{array}{l}x-3=3\\ x-3=-3\end{array}\right.\Rightarrow\left[\begin{array}{l}x=6\\ x=0\end{array}\right.\)

g:

ĐKXĐ: 2x+1>=0

=>x>=-1/2

\(\left(\sqrt{2x+1}\right)^2=25\)

=>2x+1=25

=>2x=24

=>x=12(nhận)