[tex](3\sqrt{2}-4)^{2}-5(3-2\sqrt{2}) =(3\sqrt{2})^{2}-2\cdot3\sqrt{2}\cdot4 + 4^{2} -15+10\sqrt{2} =\\\\=9\cdot2 -24\sqrt{2}+16-15+10\sqrt{2} = 18-24\sqrt{2}+16-15+10\sqrt{2} =19-14\sqrt{2}[/tex]
Wykorzystano wzór skróconego mnożenia:
[tex](a-b)^{2} = a^{2}-2ab + b^{2}[/tex]
