Đáp án + Giải thích các bước giải:
$1)x^2-6x+9=x^2-2.x.3+3^2=(x-3)^2$
$2)25-10x+x^2=5^2-2.5.x+x^2=(5-x)^2$
$3)\dfrac{1}{4}a^2+2ab^2+4b^4$
$=(\dfrac{1}{2}a)^2+2.\dfrac{1}{2}a.2b^2+(2b^2)^2$
$=(\dfrac{1}{2}a+2b^2)^2$
$4)\dfrac{1}{9}-\dfrac{2}{3}y^4+y^8$
$=(\dfrac{1}{3})^2-2.\dfrac{1}{3}.y^4+(y^4)^2=(\dfrac{1}{3}-y^4)^2$
$5)=(x+2y)(x^2-2xy+4y^2)$
$6)=(2y-5)(4y^2+10y+25)$
$7)=(a^2-b)(a^4+a^2b+b^2)$
$8)=(x-5)^2$
$9)=(2x-1/2)(4x^2+x+1/4)$
$10)=(x+2y)^2$
$8)=(3x+2-2)(3x+2+2)=3x(3x+4)$
$9)=(2x-5y)(2x+5y)$
$10)=(2x-7)(2x+7)$
$11)=(2z+3)(4z^2-6z+9)$
$12)(3/5x^2-1/2)(3/5c^2+1/2)$
$13)=(x^16-1)(x^16+1)=(x^4-1)(x^4+1)(x^16+1)$
$=(x-1)(x+1)(x^2+1)(x^4+1)(x^16+1)$
$14)=(2x+1)^2$
$15)=(x-10)^2$
$16)=(y^2-7)^2$
$17)=(5x-4y)(25x^2+20xy+16y^2)$
MK xi hay nhất ah
