Răspuns :
[tex]\it 25x^2\sqrt3+30x+3\sqrt3=25x^2\sqrt3+2\cdot3\cdot5x+3\sqrt3=\\ \\ =25x^2\sqrt3+2\cdot\sqrt3\cdot\sqrt3\cdot5x+3\sqrt3=\sqrt3\Big(5^2x^2+2\cdot5x\cdot\sqrt3+(\sqrt3)^2\Big)=\\ \\ =\sqrt3(5x+\sqrt3)^2[/tex]
[tex]\it 25x^2\sqrt3+30x+3\sqrt3=25x^2\sqrt3+2\cdot3\cdot5x+3\sqrt3=\\ \\ =25x^2\sqrt3+2\cdot\sqrt3\cdot\sqrt3\cdot5x+3\sqrt3=\sqrt3\Big(5^2x^2+2\cdot5x\cdot\sqrt3+(\sqrt3)^2\Big)=\\ \\ =\sqrt3(5x+\sqrt3)^2[/tex]