[tex]a)(4+2x)^2=4^2+2\cdot 4\cdot 2x+(2x)^2=16+16x+4x^2\\
b)(2\sqrt{2}-3a)(2\sqrt{2}+3a)=(2\sqrt{2})^2-(3a)^2=8-9a^2\\
c)(3x-2y+ \sqrt{5} )^2=(3x)^2+(2y)^2+\sqrt{5}^2-2\cdot 3x\cdot 2y+2\cdot 3x\cdot \sqrt{5}\\
-2\cdot 2y\cdot \sqrt{5}=9x^2+4y^2+5-12xy+6\sqrt{5}x-4\sqrt{5}y[/tex]