Question

solve x^2-3x-4=0

Answer 1

D = (-3)^2 - 4 * 1 * (-4) = 9 + 16 = 25
x1 = [-(-3) - sqrt(25)] / 2 = [ 3 - 5] / 2 = -2 / 2 = -1

Answer 2

x^2-3x-4=0
(x+1)(x-4)=0

Answer 3

you could always try factoring!

Answer 4

x2 = [-(-3) + sqrt(25)] / 2 = [ 3 + 5] / 2 = 8 / 2 = 4

Sorry the site crashed on me, but yea you could try factoring too, but I never really bothered learning it haha, if the question asks me to factor, I just solve it out and then do (x-x1)(x-x2) to factor which will be (x-(-1))(x-4) = (x+1)(x-4)

Answer 5

I prefer factoring if there are small numbers.
My technique is pretty easy:
x^2-3x-4=0
we have -3x and -4.
-4 is -2*2 or 4*-1 or -4*1
-3x is 1x-4x (1, -4)
so we can see that (1,-4) will be the factors