#### Answer

A. $\ square$
B. $\ 4x^2 + 4x + 1 = x + 1$

#### Work Step by Step

For letter A, the only way to eliminate said radical and solve this equation is to square both sides.
Letter B, square both sides. Squaring the radical will leave "x+1," whereas the other side will become "4x^2 + 4x +1."