Помогите с 1-5 буду благодарен :3

1)(х-2)²-(х-1)(х+2)=х²+4-4х-х²-2х+х+2=-5х+6 2)[latex] \left \{ {{3x+5y=12} \atop {x-2y=-7}} \right. [/latex] [latex] \left \{ {{3x+5y=12} \atop {-3x+6y=21}} \right. [/latex] [latex] \left \{ {{11y=33} \atop {3x+5y=12}} \right. [/latex] [latex] \left \{ {{y=3} \atop {3x+15=12}} \right. [/latex] [latex] \left \{ {{y=3} \atop {x=-1}} \right. [/latex] (-1;3)) 3)б)у=-2х+2 А(10;-18) -18=-2(10)+2 -18=-18 ответ. проходит 4)а)3х³у³+3х²у[latex] ^{4} [/latex]-6ху²=3ху²(х²у+ху²-2) б)2а+а²-б²-2б=(2а-2б)+(а²-б²)=2(а-б)+(а+б)(а-б)=(а-б)(2а+2б)