Question

a, 0,4 . \(\sqrt{0,25}\) - \(\sqrt{\frac{1}{4}}\)

b, | x - \(\frac{1}{2}\)| - \(\sqrt{\frac{1}{9}}\) = \(\sqrt{\frac{1}{4}}\)

Mọi người giúp mình với. Tối nay mình nộp rồi.

Answer 1

a. 0,4.\(\sqrt{0,25}-\sqrt{\frac{1}{4}}\)
=0,4.\(\sqrt{0,25}-\sqrt{0,25}\)
=(0,4-1).\(\sqrt{0,25}\)
=-0,6.0,5
=-0,3
b.\(|x-\frac{1}{2}|\)-\(\sqrt{\frac{1}{9}}=\sqrt{\frac{1}{4}}\)
\(|x-\frac{1}{2}|=\sqrt{\frac{1}{4}}+\sqrt{\frac{1}{9}}\)
\(|x-\frac{1}{2}|=\frac{1}{2}+\frac{1}{3}\)
\(|x-\frac{1}{2}|=\frac{5}{6}\)
\(\Rightarrow\left[{}\begin{matrix}x-\frac{1}{2}=\frac{5}{6}\\x-\frac{1}{2}=\frac{-5}{6}\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\frac{5}{6}+\frac{1}{2}\\x=\frac{-5}{6}+\frac{1}{2}\end{matrix}\right.\)
\(\Rightarrow\left[{}\begin{matrix}x=\frac{4}{3}\\x=\frac{-1}{3}\end{matrix}\right.\)
vậy x \(\in\left\{\frac{4}{3};\frac{-1}{3}\right\}\)