Solve Quadratic Equations By Factorizing

Before viewing this page, it would be helpful to learn how to Expand And Factorize Quadratic Expressions.


Example One

x2 + 7x + 12 = 0
( x + 3 ) ( x + 4 ) = 0

Either ( x + 3 ) or ( x + 4 ) equals zero

If x + 3 = 0 , then x = –3
If x + 4 = 0 , then x = –4

x = –3 or –4


Example Two

x2 + 8x + 12 = 0
( x + 6 ) ( x + 2 ) = 0

Either ( x + 6 ) = 0, or ( x + 2 ) = 0

If x + 6 = 0 , then x = –6
If x + 2 = 0 , then x = –2

x = –2 or –6


Example Three

2x2 – 7x – 15 = 0
( 2x + 3 ) ( x – 5 ) = 0

Either ( 2x + 3 ) = 0, or ( x – 5 ) = 0

If 2x + 3 = 0 , then x = –1.5
If x – 5 = 0 , then x = 5

x = –1.5 or 5

Questions - Solve these Quadratic Equations by Factorizing

Q1. x2 – 12x + 35 = 0
Q2. x2 + 6x – 16 = 0
Q3. 3x2 – 12 = 0

Answers
A1. x = 5 or 7
A2. x = 2 or –8
A3. x = 4