Chapter 10 - Radical Expressions and Equations - 10-4 Solving Radical Equations - Practice and Problem-Solving Exercises - Page 637: 28

$a=\frac{-1}{2}$ is extraneous.

$2a=\sqrt 4a+3$ With $a=\frac{3}{2}$ then $2(\frac{3}{2})=\sqrt 4(\frac{3}{2})+3$ $3=3$ With $a=\frac{-1}{2}$ then $2(\frac{-1}{2})=\sqrt 4(\frac{-1}{2})+3$ $-1 \ne 1$ traneous.Hence, $a=\frac{-1}{2}$ is ex