Đáp án:

Giải thích các bước giải:

$5x^2-10xy+5y^2-20z^2$

$=5(x^2-2xy+y^2-4z^2)$

$=5[(x+y)^2-4z^2]$

$=5(x+y-2z)(x+y+2z)$

$16x-5x^2-3$

$=-(5x^2-16x+3)$

$=-(5x^2-15x-x+3)$

$=-[5x(x-3)-(x-3)]$

$=-5x(x-3)+(x-3)$

$=(-5x+1)(x-3)$

$x^2-5x+5y-y^2$

$=(x^2-y^2)-(5x-5y)$

$=(x-y)(x+y)-5(x-y)$

$=(x-y)(x+y-5)$

$3x^2-6xy+3y^2-12z^2$

$=3(x^2-2xy+y^2-4z^2)$

$=3[(x^2-2xy+y^2)-4z^2]$

$=3[(x-y)^2-4z^2]$

$=3(x-y-2z)(x-y+2z)$

$x^2+4x+3$

$=(x^2+x)+(3x+3)$

$=x(x+1)+3(x+1)$

$=(x+3)(x+1)$

$(x^2+1)^2-4x^2$

$=(x^2+1-2x)(x^2+1+2x)$

$=(x^2-2x+1)(x^2+2x+1)$

$=(x-1)^2(x+1)^2$

$x^2-4x-5$

$=x^2+x-5x-5$

$=(x^2+x)-(5x+5)$

$=x(x+1)-5(x+1)$

$=(x-5)(x+1)$

$3x^3y^2:x^2$

$=3xy^2$

Chúc bạn học tốt . Xin cau trả lời hay nhất ạ

Đáp án:

Giải thích các bước giải:

$1)5x^2-10xy+5y^2-20z^2$

$=5(x^2-2xy+y^2-4z^2)$

$=5[(x^2-2xy-y^2)-4z^2]$

$=5[(x-y)^2-(2z)^2]$

$=5(x-y-2z)(x-y+2z)$

$2)16x-5x^2-3$

$=15x-5x^2+x-3$

$=(15-5x^2)-(3-x)$

$=5x(3-x)-(3-x)$

$=(5x-1)(3-x)$

$3)x^2-5x+5y-y^2$

$=(x^2-y^2)-(5x-5y)$

$=(x-y)(x+y)-5(x-y)$

$=(x-y)(x+y-5)$

$4)3x^2-6xy+3y^2-12z^2$

$=3(x^2-2xy+y^2-4z^2)$

$=3[(x^2-2xy-y^2)-4z^2]$

$=3[(x-y)^2-(2z)^2]$

$=3(x-y-2z)(x-y+2z)$

$5)x^2+4x+3$

$=x^2+x+3x+3$

$=(x^2+x)+(3x+3)$

$=x(x+1)+3(x+1)$

$=(x+1)(x+3)$

$6)(x^2+1)^2-4x^2$

$=(x^2+1)^2-(2x)^2$

$=(x^2+1-2x)(x^2+1+2x)$

$=(x-1)^2(x+1)^2$

$7)x^2-4x-5$

$=x^2+x-5x-5$

$=(x^2+x)-(5x+5)$

$=x(x+1)-5(x+1)$

$=(x+1)(x-5)$

$8)3x^3y^2÷x^2$

$=3.(x^3÷x^2).y^2$

$=3xy^2$