QUADRATICS A1

 What must be added to x²  + 14x to make the expression a perfect square?

 

Solution

 

a=1, b=14,c=?

 

b² = 4ac

 

(14)² = 4 x 1 x c

 

196 = 4c

 

196 = 4c      [dividing by 4 both sides]

4        4

 

49 = c

 

Hence number to be added is 49

 

TRY THIS……………………

 

What must be added to x²  + 20x to make the expression a perfect square?