Question

What is the solution set for \sqrt{x+5} = 4\sqrt{x}?
Choose one answer.
a. {\frac{1}{3}}
b. {-1, \frac{1}{3}}
c. {-1}
d. {1, \frac{-1}{3}}

Answer 1

Square both sides. Solve for x. Put x back into the original equation and make sure it satisfies the equation.

Answer 2

surely it is not -1 because the right hand side is \(\sqrt x\)
so that we can eliminate b and c and even d, hihihihi...