Chapter 2: Notes

• Solve (x + 1)(x – 3) = 0 

          (x + 1)(x – 3) = 0

x + 1 = 0  or  x – 3 = 0
x = –1  or  x = 3
The solution is  x = –1, 3 

• Solve x² – 3x – 4 = 0.

x² – 3x – 4 = 0
(x + 1)(x – 4) = 0
x + 1 = 0  or  x – 4 = 0
x = –1  or  x = 4 
The solution is x = –1, 4

• Solve x² – 4 = 0

          x² – 4 = 0
      (x + 2)(x – 2) = 0
      x + 2 = 0  or  x – 2 = 0
      x = –2  or  x = 2

        The solution is x = ± 2

• Solve x² – 7x = 0.

x² – 7x = 0
x(x – 7) = 0
x = 0  or  x – 7 = 0
x = 0  or  x = 7 
The solution is x = 0, 7