Question

Tìm x:

 

Answer 1

13: ĐKXĐ: x>=3/2

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

=>\(2x-3=\left(\dfrac{1}{2}\right)^2=\dfrac{1}{4}\)

=>\(2x=3+\dfrac{1}{4}=\dfrac{13}{4}\)

=>\(x=\dfrac{13}{8}\left(nhận\right)\)

14: ĐKXĐ: x>=-7/3

\(\sqrt{3x+7}=\dfrac{2}{3}\)

=>\(3x+7=\left(\dfrac{2}{3}\right)^2=\dfrac{4}{9}\)

=>\(3x=\dfrac{4}{9}-7=\dfrac{4}{9}-\dfrac{63}{9}=-\dfrac{59}{9}\)

=>\(x=-\dfrac{59}{9}:3=-\dfrac{59}{27}\left(nhận\right)\)

15: ĐKXĐ: x>=3/10

\(\sqrt{10x-3}=\dfrac{2}{5}\)

=>\(10x-3=\left(\dfrac{2}{5}\right)^2=\dfrac{4}{25}\)

=>\(10x=3+\dfrac{4}{25}=\dfrac{79}{25}\)

=>\(x=\dfrac{79}{250}\left(nhận\right)\)