Answer:
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
Step-by-step explanation:
next method
x²+2×x×3+3²=0
it is in formula of (x+y)²
(x+3)²=0
x+3=√0
