Answer
a. $x^2+6x+9$
b. $x^2+10x+25$
Work Step by Step
a. $(x+3)^2=(x+3)(x+3)$
Use the Distributive Property:
$(x+3)(x+3)=x(x+3)+3(x+3)$
$=x^2+3x+3x+9$
$=x^2+6x+9.$
b. $(x+5)^2=(x+5)(x+5)$
Use the Distributive Property:
$(x+5)(x+5)=x(x+5)+5(x+5)$
$=x^2+5x+5x+25$
$=x^2+10x+25.$
