Maths, x=...? Please Help.

(x-3)(x+1) > 0

consider(x-3)(x+1) =0
x=3 or-1

put x= a no. between -1 and 3(e.g.0) into y=(x-3)(x+1)

y=-3＜0

so -1＜x＜3 is not the solution

so x< -1 or x > 3

(x-3)(x+1) > 0
x > 3 or x > -1

(x-3) 或 (x+1)必然會=0
因為:
2x0=0
5x0=0
20x0=0
所以:
(x-3) > 0 or (x+1) > 0
x > 3 or x > -1

希望你會明啦!!!!!!!!!!!!!!!!!!!!!!!!

(x-3)(x+1) > 0

x'square + x - 3x - 3 > 0

x'square - 2x > 3

... 之後唔知了... 太耐無計數, 唔記得晒了 =.=