---

Status: Waiting for your answers.

Problem: Solve for the variable. Check a value if it is extraneous.   √ f + 7  = f - 5   f + 7 = ( f + )2   f + 7 = f2 + f +   0 = f2 + f +   0 = ( f + )( f + )   f1 =     f2 = extraneous   extraneous