x^2+10x+25
=(x+5)^2
y^2+14y+49
=(y+7)^2
2z^2+12z+18
=2(z^2+6z+9)
=2(z+3)^2
x^2-8x+16
=(x-4)^2
a^2-12a+36
=(a-6)^2
3b^2-6b+3
=3(b^2-2b+1)
=3(b-1)^2
6p^4-24q^2
=6(p^4-4q^2)
=6(p^2+2q)(p^2-2q)
2p^4-18p^2q^2
=2p^2(p^2-9q^2)
=2p^2(p+3q)(p-3q)
x^4y^2-4x^2y^4
=x^2y^2(x^2-4y^2)
=x^2y^2(x+2y)(x-2y)
32xy^4-2x^5
=2x(16y^4-x^4)
=2x(4y^2+x^2)(4y^2-x^2)
=2x(4y^2+x^2)(2y+x)(2y-x)
642^4-4b^4
=(642^2+2b^2)(642^2-2b^2)
=16(321^2+b^2)(321^2-b^2)
=16(103042+b^2)(321+b)(321-b)