generally, if I don't see right off that it will factor (as will #1), I check the discriminant. If it is a perfect square (as with #2) then I know it will factor, and I just look at it a bit more. If it still doesn't seem obvious, then I know I can easily use the QF to pry out the rational roots.
Other than that, only experience will give you a feel for the kinds of quadratics that yield to which method.
Methods: Factoring, completing the square, quadratic formula.
for these equations:
1. x^2 - x = 6
2. -2x^2 + 5x - 3 = 0
3. 3x^2 + x + 1 = 0
4. 2x(x - 5) = -12
is there any reason to chose one method over the other to solve the equations if so which one for each?
1 answer
1 answer