Đáp án+Giải thích các bước giải:
$1) x²+6x-y²+9$
$=(x²+6x+9)-y²$
$=(x+3)²-y²$
$=(x+3-y)(x+3+y)$
$2) 2x-4y+xz-2yz$
$=(2x-4y)+(xz-2yz)$
$=2(x-2y)+z(x-2y)$
$=(x-2y)(2+z)$
$3) 2x²+13x+15$
$=2x²+10x+3x+15$
$=2x(x+5)+3(x+5)$
$=(x+5)(2x+3)$
$4) x^4-4x³+8x²-16x+16$
$=x^4-2x³-2x³+4x²+4x²-8x-8x+16$
$=(x^4-2x³)-(2x³+4x²)+(4x²-8x)-(8x+16)$
$=x³(x-2)-2x²(x-2)+4x(x-2)-8(x-2)$
$=(x-2)(x³-2x²+4x-8)$
$=(x-2)[(x³-2x²)+(4x-8)]$
$=(x-2)[x²(x-2)+4(x-2)]$
$=(x-2)²(x²+4)$
Chúc bn hc tốt🥰
`\text{#LinhSad}`
