Solve quadratic equation(1)


Solve quadratic equation by factoring
     ( easy math)
Example 1 :
Solve the following equation
X2 + 11 x + 28 =0
the answer :
( x + 4) (x + 7 ) =0
X + 4 = 0       or       x + 7 = 0
X = - 4                       x = - 7
the solution to this equation = { - 4 , - 7 }

Example 2 :
Solve the following equation
X2 - 9 x + 20 =0
the answer :
( x - 4) (x - 5 ) =0
X - 4 = 0       or       x - 5 = 0
X =   4                       x =   5
the solution to this equation = {  4 , 5 }

Example 3 :
Solve the following equation
X2 - 2 x - 35 =0
the answer :
( x + 5) (x - 7 ) =0
X + 5 = 0       or       x - 7 = 0
X = - 5                       x =   7
the solution to this equation = { - 5 ,  7 }

Example 4 :
Solve the following equation
X2  - 36 =0
the answer :
( x + 6) (x - 6 ) =0
X + 6 = 0       or       x - 6 = 0
X = - 6                       x = 6
the solution to this equation = { - 6 , 6 }

Example 5 :
Solve the following equation
X2 + 3 x   =0
the answer :
  x (x + 3 ) =0
X  = 0       or       x + 3 = 0
X = 0                       x = - 3
the solution to this equation = { 0 , - 3 }

Example 6 :
Solve the following equation
X2 – 5 x = 0 2
the answer :
 x (2 x – 5 )   = 0
X   = 0       or      2 x - 5 = 0
X = 0                       x =   5/2
the solution to this equation = { 0 , 5/2 }

Example 7 :
Solve the following equation
X  ( x + 2 ) =  24
the answer :
x2 + 2 x – 24 =0
( x - 4) (x + 6 ) =0
X - 4 = 0       or       x + 6 = 0
X =  4                       x = - 6
the solution to this equation = {  4 , - 6 }

Example 8 :
Solve the following equation
X  + 3 )2  = 100)
the answer :
we have the square root
( x + 3) = 10     or    (x + 3 ) = -10
X = 10 -3                   x = - 10 - 3
X = 7                       x = - 13
the solution to this equation = { 7 , - 13 }

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