$\text{~~Holi~~}$
$\text{_bài làm_}$
$a. x³-2x²+x = x.x.x-2.x.x+x = x(x²-2x+1) = x(x²-2x+1²) = x(x-1)²$
$b. x²-2xy+y²-5x+5y = (x²-2xy+y²)-(5x-5y) $
$= (x-y)²-5(x-y) = (x-y)(x-y)-5(x-y) = (x-y)(x-y-5)$
$c. 3x+3y+x²+xy = (3x+3y)+(x²+xy) = 3(x+y)+x(x+y) = (x+y)(3+x)$
$d. x²-9x+20 = x²-4x-5x+20 = (x²-4x)-(5x-20) = x(x-4)-5(x-4) = (x-4)(x-5)$
$e. 10x²+13x-3 = 10x²+15x-2x-3 = (10x²+15x)-(2x+3) = 5x(2x+3)-(2x+3) = (2x+3)(5x-1)$