Obliczenia
[tex](2x-5y)^2=(2x)^2-2\cdot2x\cdot5y+(5y)^2=\boxed{4x^2-20xy+25y^2}\\\\(4x+y)^2=(4x)^2+2\cdot4x\cdot y+y^2=\boxed{16x^2+8xy+y^2}\\\\(x-\sqrt2)(x+\sqrt2)=x^2-(\sqrt2)^2=\boxed{x^2-2}\\\\(1-\sqrt5)^2=1^2-2\cdot1\cdot\sqrt5+(\sqrt5)^2=1-2\sqrt5+6=\boxed{6-2\sqrt5}[/tex]
Wykorzystane wzory
[tex](a-b)(a+b)=a^2-b^2\\\\(a+b)^2=a^2+2ab+b^2\\\\(a-b)^2=a^2-2ab+b^2[/tex]
