Question

Tìm x,biết :

a) \(\sqrt{3\left(x-2\right)}=7\)

b) \(\sqrt{4\left(x-2\right)^2}-1=0\)

c) \(3\sqrt{x+5}=7\)

Help cái nà :)

Answer 1

a. \(\sqrt{3\left(x-2\right)}=7\)

\(\Leftrightarrow3\left(x-2\right)=49\Leftrightarrow x-2=\dfrac{49}{3}\Leftrightarrow x=\dfrac{55}{3}\)

b. \(\sqrt{4\left(x-2\right)^2}-1=0\Leftrightarrow2\left(x-2\right)=1\Leftrightarrow x-2=\dfrac{1}{2}\Leftrightarrow x=\dfrac{5}{2}\)

c. \(3\sqrt{x+5}=7\Leftrightarrow\sqrt{x+5}=\dfrac{7}{3}\Leftrightarrow x+5=\dfrac{49}{9}\Leftrightarrow x=\dfrac{4}{9}\)

Answer 2

Bạn xem thêm nhé :

\(b.\sqrt{4\left(x-2\right)^2}-1=0\)

⇔ \(\text{ |}2\left(x-2\right)\text{ |}=1\)

⇔ \(2x-4=1\) hoặc \(2x-4=-1\)

⇔ \(x=\dfrac{5}{2}\) hoặc \(x=\dfrac{3}{2}\)

KL.............