Thread: How many answers to problem with radical?

Here's the problem:

x - 3 = sqrt(4x)

I know x = 9 is one of the answers, but is x = 1 also an answer? Thanks.

x = 1 is an extraneous root that results from squaring both sides of the equation. While it satisfies the resulting quadratic, it does not satisfy the original equation, and so it is discarded as extraneous.