Cześć ;-)
a]
[tex]2(x+4)^2=2(x^2+2\cdot x\cdot4+4^2)=\\\\=2(x^2+8x+16)=\boxed{2x^2+16x+32}[/tex]
b]
[tex](3x-6)^2=(3x)^2-2\cdot3x\cdot6+6^2=\\\\=\boxed{9x^2-36x+36}[/tex]
c]
[tex](x+y)^2-(y-5)^2=\\\\=x^2+2\cdot x\cdot y+y^2-(y^2-2\cdot y\cdot5+5^2)=\\\\=x^2+2xy+y^2-(y^2-10y+25)=\\\\=x^2+2xy+y^2-y^2+10y-25=\\\\=\boxed{x^2+2xy+10y-25}[/tex]
Użyte wzory skróconego mnożenia
[tex](a+b)^2=a^2+2ab+b^2[/tex]
[tex](a-b)^2=a^2-2ab+b^2[/tex]
Pozdrawiam! ~ JulkaOdMatmy
