#### [Problem of the day][数学挑战][Algebra][代数][4] MathematicsAlgebra

2020-5-4 294

Given $$\huge \sqrt{x^2 + 25} - \sqrt{x^2 - 15} = 4.$$ What is the value of $$\huge \sqrt{x^2 + 25} + \sqrt{x^2 - 15} = ?$$