Question

lm hộ m bài 2,3,4,5 với cần gấp lắm

Answer 1

Bài 2: 

a: Ta có: \(\sqrt{3x^2+1}=5\)

\(\Leftrightarrow3x^2+1=25\)

\(\Leftrightarrow3x^2=24\)

\(\Leftrightarrow x^2=8\)

hay \(x\in\left\{2\sqrt{2};-2\sqrt{2}\right\}\)

b: Ta có: \(\sqrt{2-3x}=4+\sqrt{6-2\sqrt{5}}-\sqrt{5}\)

\(\Leftrightarrow\sqrt{2-3x}=4+\sqrt{5}-1-\sqrt{5}\)

\(\Leftrightarrow2-3x=9\)

\(\Leftrightarrow3x=11\)

hay \(x=\dfrac{11}{3}\)