CBSE Class 9 Answered

This is "quadratic equals zero", but, unlike the previous example, this isn't yet factored. The quadratic must first be factored, because it is only when you MULTIPLY and get zero that you can say anything about it. You can't conclude anything about the individual terms of the unfactored quadratic (like the 5x or the 6), because you can add lots of stuff that totals zero.

So the first thing I have to do is factor:

x² + 5x + 6 =x² + 3x+2x  + 6 = (x + 2)(x + 3)

Set this equal to zero:

(x + 2)(x + 3) = 0

Solve each factor: Co

x + 2 = 0  or  x + 3 = 0
x = –2  or  x = – 3pyright © Elizabeth Stapel 2006-2008 All Rights Reserved