Question

Find the discriminant of x²+6x+9=0 ​

Answer 1

x²+6x+9=0

x²+3x+3x+9=0

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

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

either

x+3=0

x=-3

or

x+3=0

x=-3

Explanation:

next method

x²+6x+9=0

x²+2×x×3+3²=0

it is in formula of (x+y)²

(x+3)²=0

x+3=√0

x+3=0

x=-3