If ax2+bx+c=0 is a general quadratic equation, then for x2-3x-1=0 a=1, b=-3, c=-1, the coefficients.
Quadratic formula is x=(-b±√(b2-4ac))/2a. Plus-or-minus (±) means there are (usually) two solutions for x, depending on whether we subtract the square root expression or add it.
So in the example we substitute for a, b and c:
x=(-(-3)±√((-3)2-4×1×(-1)))/2=(3±√(9+4))/2=(3±√13)/2=(3+√13)/2=(3+3.6056)/2=3.3028 or (3-√13)/2=(3-3.6056)/2=-0.3028.
ANSWER: x=3.3028 or x=-0.3028 (approximate figures).