\(\left(2x+3\right)^2=\frac{9}{121}\)
\(\left(2x+3\right)^2=\left(\frac{3}{11}\right)^2\)
\(\Rightarrow2x+3=\frac{3}{11}\text{ hoặc }2x+3=\frac{-3}{11}\)
\(2x=\frac{3}{11}-3\text{ hoặc }2x=\frac{-3}{11}-3\)
\(2x=\frac{3}{11}-\frac{33}{11}\text{ hoặc }2x=\frac{-3}{11}-\frac{33}{11}\)
\(2x=\frac{-30}{11}\text{ hoặc }2x=\frac{-36}{11}\)
\(x=\frac{-30}{11}:2\text{ hoặc }x=\frac{-36}{11}:2\)
\(x=\frac{-30}{11}.\frac{1}{2}\text{ hoặc }x=\frac{-36}{11}.\frac{1}{2}\)
\(x=\frac{-15}{11}\text{ hoặc }x=\frac{-18}{11}\)