Question

ai giúp mik với :((

tìm x biết

\(\sqrt{x+2}=\frac{5}{7}\)

Answer 1

giú mik với m.n =(((

Answer 2

\(\sqrt{x+2}\)= \(\frac{5}{7}\) \(\Rightarrow\) x + 2 = \(\frac{5^2}{7^2}\)

                                            x + 2 = \(\frac{25}{49}\)

                                            x       = \(\frac{25}{49}\) - 2 = \(\frac{-73}{49}\)

Answer 3

\(\sqrt{x+2}=\frac{5}{7}\Rightarrow\left(\sqrt{x+2}\right)^2=\left(\frac{5}{7}\right)^2\)

\(\Rightarrow x+2=\frac{25}{49}\Rightarrow x=\frac{25}{49}-2\Rightarrow x=\frac{25-49.2}{49}\)

\(\Rightarrow x=\frac{-73}{49}\)

Vậy...

Answer 4

\(\sqrt{x}+2=\frac{5}{7}\)

\(\Leftrightarrow\)\(\sqrt{x}=\frac{5}{7}-2\)

\(\Leftrightarrow\)\(\sqrt{x}=\frac{5}{7}-\frac{14}{7}\)

\(\Leftrightarrow\)\(\sqrt{x}=\frac{9}{7}\)

\(\Leftrightarrow\)\(x=\frac{9^2}{7}\)

\(\Leftrightarrow\)\(x=\frac{81}{49}\)

      Vậy \(x=\frac{81}{49}\)