First, add #color(red)(sqrt(4x))# to both sides of the equation:
#sqrt(2x + 1) - sqrt(4x) + color(red)(sqrt(4x)) = 0 + color(red)(sqrt(4x))#
#sqrt(2x + 1) - 0 = color(red)(sqrt(4x))#
#sqrt(2x + 1) = sqrt(4x)#
Next, square both sides of the equation to eliminate the radicals while keeping the equation balanced:
#(sqrt(2x + 1))^2 = (sqrt(4x))^2#
#2x + 1 = 4x#
Then, subtract #color(red)(2x)# from each side of the equation to isolate the #x# term while keeping the equation balanced:
#-color(red)(2x) + 2x + 1 = -color(red)(2x) + 4x#
#0 + 1 = (-color(red)(2) + 4)x#
#1 = 2x#
Now, divide each side of the equation by #color(red)(2)# to solve for #x# while keeping the equation balanced:
#1/color(red)(2) = (2x)/color(red)(2)#
#1/2 = (color(red)(cancel(color(black)(2)))x)/cancel(color(red)(2))#
#1/2 = x#
#x = 1/2#
Or
#x = 0.5#