Question

sqrt(9x+55)=x+5

Answer 1

By squaring both sides, we have
\[ 9x+55=x^2+10x+25\]
Hence, it is reduced to the following quadratic equation
\[ x^2+x-30 =0\]
This gives
\[ x=5 ; x=-6 \]
However, by substituting back to the original equation, we only accept the root
\[ x=5\]

Answer 2

No, -6 cannot be the solution, take a look at the original equation.

Answer 3

x=5