Stim asta:
[tex](a+b)^2=a^2+2ab+b^2\\
(a-b)^2=a^2-2ab+b^2[/tex]
a)
[tex]x^2+4x+4=x^2+2\cdot2\cdot x+2^2=(x+2)^2[/tex]
b)
[tex]1-2x \sqrt{5}+5x^2=1^2-2\cdot1\cdot (x \sqrt{5}) +(x \sqrt{5} )^2=(x \sqrt{5}-1 )^2[/tex]
c)
[tex]3x^4-6x^2 \sqrt{3} +9=(x^2 \sqrt{3} )^2-2\cdot3\cdot (x^2 \sqrt{3})+3^2=\\
=(x^2 \sqrt{3} -3)^2[/tex]
