Question

What are the solution(s) to the quadratic equation 40 − x2 = 0?

Answer 1

`40-x^2=0\\ x^2=40\\ x=-√(40) \vee x=√(40)\\ x=-2√(10) \vee x=2√(10)`

Answer 2

`40-x^2=0\ \ \ |add\ x^2\ to\ both\ sides\\\\x^2=40\iff x=\pm√(40)\\\\x=-√(4\cdot10)\ or\ x=√(4\cdot10)\\\\x=-\sqrt4\cdot√(10)\ or\ x=\sqrt4\cdot√(10)\\\\\boxed{x=-2√(10)\ or\ x=2√(10)}`