a) x^2+2xy+y^2=(x+y)^2
b)x^2+2x+1=x^2+2x*1+1^2=(x+1)^2
c)x^2+4x+4=x^2+2x*2+2^2=(x+2)^2
d)y^2+6y+9=y^2+2y*3+3^2=(y+3)^2
e)x^2+8x+16=x^2+2x*4+4^2=(x+4)^2
f) b^2+10b+25=b^2+2b*5+5^2=(b+5)^2
g)x^2+12x+36=x^2+2x*6+6^2=(x+6)^2
h)4x^2+12x+9=2^2*x^2+2*2x*3*3^2=(2x)^2+2*2x*3+3*2=(2x+3)^2
i)9x^2+12x+4=3^2*x^2+2*3x*2+2^2=(3x)^+2*3x*2+2^2=(3x+2)^2
