Question

[NT Ánh]

Giair phương trình:

a) \(\sqrt{2}\).x - \(\sqrt{50}\)=0

b) \(\sqrt{3}\).x + \(\sqrt{3}\)=\(\sqrt{12}\)+\(\sqrt{27}\)

c) \(\sqrt{3}\).x\(^2\)- \(\sqrt{12}\)=0

d) \(\frac{x^2}{\sqrt{5}}\) - \(\sqrt{20}\)=0

Answer 1

[Trần Việt Linh]

a) \(\sqrt{2}x-\sqrt{50}=0\)

\(\Leftrightarrow\sqrt{2}x=\sqrt{50}\)

\(\Leftrightarrow x=\frac{\sqrt{50}}{\sqrt{2}}=\sqrt{\frac{50}{2}}=\sqrt{25}=5\)

b) \(\sqrt{3}x+\sqrt{3}=\sqrt{12}+\sqrt{27}\)

\(\Leftrightarrow\sqrt{3}\left(x+1\right)=2\sqrt{3}+3\sqrt{3}\)

\(\Leftrightarrow\sqrt{3}x=5\sqrt{3}\)

\(\Leftrightarrow x=5\)

c) \(\sqrt{3}x^2-\sqrt{12}=0\)

\(\Leftrightarrow\sqrt{3}\left(x^2-2\right)=0\)

\(\Leftrightarrow x^2-2=0\)

\(\Leftrightarrow x^2=2\Leftrightarrow\left[\begin{array}{nghiempt}x=\sqrt{2}\\x=-\sqrt{2}\end{array}\right.\)

d) \(\frac{x^2}{\sqrt{5}}-\sqrt{20}=0\)

\(\Leftrightarrow\)\(\frac{1}{\sqrt{5}}\left(x^2-10\right)=0\)

\(\Leftrightarrow x^2-10=0\)

\(\Leftrightarrow x^2=10\Leftrightarrow\left[\begin{array}{nghiempt}x=\sqrt{10}\\x=-\sqrt{10}\end{array}\right.\)