Solving radical equations are different because you would want to get everything in the equation to rational numbers. Extraneous solutions arise when you manipulate the equation. After manipulating if a solution is found that can not satisfy the original equation(s).
The exact conversion factor is 1/0.3048, so the area is closer to 1765 ft². For a 4-significant digit answer, you need to use a conversion factor accurate to 4 significant digits.
