3(x+1)^2-5(x+1)(x-1)+2(x-1)^2等於多少?

3(x+1)^2-5(x+1)(x-1)+2(x-1)^2等於多少?


3(x+1)²;-5(x+1)(x-1)+2(x-1)²;
=[(x+1)-(x-1)][3(x+1)-2(x-1)]
=2(x+5)
=2x+10



2/x+(3/x+2)等於


2/x+3/(x+2)=12(x+2)+3x=x(x+2)2x+4+3x=x²;+2xx²;-3x-4=0(x-4)(x+1)=0x1=4 x2= -1



(x-2)(x-3)等於多少
(x-2)(x-3)答案和步驟給我


(x-2)(x-3)=x^2-3x-2x+6=x^2-5x+6,就是(A-B)(A-C)=A^2-(B+C)X+BC