Solve the equation x^2-4x-12=0 two ways. By factoring and by Quadratic formula

By factoring, find two values j and k which satisfy two conditions, jk=ac=-12 and j+k=b=-4, so j and k must be 2 and - 6 so the factors are:

(x+2) (x-6) = 0

So x=-2 and 6

By the quadratic formula, x = (-b±√ (b^2-4ac)) / (2a), in this case:

x = (4±√ (16+48)) / 2

x = (4±√64) / 2

x = (4±8) / 2

x=2±4

x=-2 and 6