Respuesta :

gmany

Answer:

c = 9

Step-by-step explanation:

[tex](a+b)^2=a^2+2ab+b^2\\\\\text{We have}\ x^2+6x+c=x^2+2(x)(3)+c\\\\\text{Therefore}\ c=3^2=9\\\\x^2+2(x)(3)+3^2=(x+3)^2[/tex]