Use the Quadratic Formula.
In general, given ax^2 + bx + c = 0, there are two solutions that exist, where;
x = -b + √b^2 - 4ac/2a , -b √b^2 - 4ac/2a
In this case, a = 1, b = -5, and c = -7
x = 5 + √(-5)^2 - 4 * -7/2 , 5 - √(-5)^2 - 4 * -7/2
Simplify
[tex]x = \frac{5+\sqrt{53} }{2} , \frac{5-\sqrt{23} }{2}[/tex]
