Question

What are the solutions to the quadratic equation 98-x2=0

Answer 1

$98-x^2=0\qquad\text{add}\ x^2\ \text{to both sides}\\\\98=x^2\to x^2=98\\\\x=\pm\sqrt{98}\\\\x=\pm\sqrt{49\cdot2}\\\\x=\pm\sqrt{49}\cdot\sqrt2\\\\\boxed{x=-7\sqrt2\ \vee\ x=7\sqrt2}$