x3 - 36 has no real solution. It factors to
(x - 3.30193)(x + (1.65096 - 2.85955i))(x + (1.65096 + 2.85955i)) where i is the square root of -1.
x squared -2x-3 equals 0 is the same as (x + 1)(x - 3) = 0
(x+3)(x-4)
(x + 6)(x - 6)
(x-3)(x-5) = 0
(x-3)(x-9) = 0
(x+4)(x-5) = 0
Suppose x3-4x = 0. To solve, factor: x3-4x = x(x2-4) = x(x+2)(x-2) = 0 Now, a product equals 0 if and only one or more of the factors equals 0, so set each factor to 0 and solve. The roots are 0,-2 and +2.
4(x + 1) = 0.
x^2+4x=0 x(x+4)=0 x=0 and x+4=0 x=0 and x=-4
63
(x - 6)(x - 2)
2x^3(x - 3)(x + 3)