Question

How to solve and why the answer is (A)

Answer 1

`(1)/(2)x^2+mx=5\\ (1)/(2)x^2+mx-5=0\\\\ \Delta=m^2-4\cdot(1)/(2)\cdot(-5)=m^2+10\\ √(\Delta)=√(m^2+10)\\\\ x=(-m\pm√(m^2+10))/(2\cdot(1)/(2))=-m\pm√(m^2+10)`