Ax BX +C 0 Ax BX +C 0: Grade 9 Summarized Module
Ax BX +C 0 Ax BX +C 0: Grade 9 Summarized Module
Ax BX +C 0 Ax BX +C 0: Grade 9 Summarized Module
SUMMARIZED MODULE
QUADRATIC EQUATION
The learner illustrates quadratic equations. Solves quadratic equations by extracting the square
roots, factoring, completing the square and using the quadratic formula.
An equation that can be written in the form ax 2 +bx +c=0 , where a, b and c are real numbers
with a≠ 0, is a quadratic equation in general form. The name quadratic comes from “quad” meaning
square. If the quadratic equation is written ax 2 +bx +c=0 in which all the nonzero terms on the left side
equating to 0, it is said to be a quadratic equation in general form. A quadratic equation is called a second
degree equation because the left side is a polynomial of degree 2.
Illustrative examples
Write each of these quadratic equation in general form and identify the real numbers a, b and c.
1. m 2 +7 m−8=0
Solution
2. 4 x2 −3 x =5
Solution
4 x2 −3 x −5=0 the equation in general form. Thus a=4, b=-3 and c=-5
Example:
Solution:
Example:
Solution:
1. Move all terms to the same side of the equal sign, so x 2−x−6=0
the equation is set equal to 0. This places the equation in general form
2. Factor the algebraic expression (x-3)(x+2) are called factors. These are
the factors of the equation x 2−x−6 .
3. Set each factor equal to 0.this process is called the x-3=0; x+2=0
“zero product property”. If the product of two factors
equal to 0, then either one or both of the factors must
be 0.
4. Solve each resulting equation. x=3 and x= -2 are called roots. These are
the roots of the equation x 2−x−6=0