Cześć ;-)
a]
[tex]3(2-y)^2+2(y-5)^2=\\\\=3(2^2-2\cdot2\cdot y+y^2)+2(y^2-2\cdot y\cdot5+5^2)=\\\\=3(y^2-4y+4)+2(y^2-10y+25)=\\\\=3y^2-12y+12+2y^2-20y+50=\boxed{5y^2-32y+62}[/tex]
b]
[tex](3x-2y)^2=(3x)^2-2\cdot3x\cdot2y+(2y)^2=\\\\=\boxed{9x^2+4y^2-12xy}[/tex]
c]
[tex](x-2)^2+2x-3=(x^2-2\cdot x\cdot2+2^2)+2x-3=\\\\=x^2-4x+4+2x-3=\boxed{x^2-2x+1}[/tex]
Wykorzystany wzór skróconego mnożenia
[tex](a-b)^2=a^2-2ab+b^2[/tex]
Pozdrawiam! ~ JulkaOdMatmy
