làm giúp ạ !!!!!!!!!!!!!!!!!!!!!!!!!!!!!11

gacon8177

2 năm trước

Loga Sinh Học lớp 12

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phuonglinhtrinh3008

`***`Lời giải`***`

`-2x^3y(2x^2-3y+5yz)`

`=-2x^3y.2x^2-2x^3y.-3y-2x^3y.5yz`

`=-4x^5y+6x^3y^2-10x^3y^2z`

`(x-2y)(x^2y^2-xy+2y)`

`=x(x^2y^2-xy+2y)-2y(x^2y^2-xy+2y)`

`=x^3y^2-x^2y+2xy-2x^2y^3+2xy^2-4y^2`

`2/3x^2y(3xy-x^2+y)`

`=2/3x^2y.3xy+2/3x^2y.-x^2+2/3x^2y.y`

`=2x^3y^2-2/3x^4y+2/3x^2y^2`

`(x-y)(x^2+xy+y^2)`

`=x^3-y^3`

Áp dụng: `A^3-B^3=A^2+AB+B^2`

Vote (0) Phản hồi (0) 2 năm trước

sunshine110900

Đáp án:

\(\begin{array}{l}
a) - 4{x^5}y + 6{x^3}{y^2} - 10{x^3}{y^2}z\\
d)2{x^3}{y^2} - \dfrac{2}{3}{x^4}y + \dfrac{2}{3}{x^2}{y^2}\\
b){x^3}{y^2} - {x^2}y + 2xy - 2{x^2}{y^3} + 2x{y^2} - 4{y^2}\\
d){x^3} - {y^3}
\end{array}\)

Giải thích các bước giải:

\(\begin{array}{l}
a) - 2{x^3}y.2{x^2} + 2{x^3}y.3y - 2{x^3}y.5yz\\
= - 4{x^5}y + 6{x^3}{y^2} - 10{x^3}{y^2}z\\
d)\dfrac{2}{3}{x^2}y.3xy - \dfrac{2}{3}{x^2}y.{x^2} + \dfrac{2}{3}{x^2}y.y\\
= 2{x^3}{y^2} - \dfrac{2}{3}{x^4}y + \dfrac{2}{3}{x^2}{y^2}\\
b)x.{x^2}{y^2} - x.xy + 2xy - 2y.{x^2}{y^2} + 2y.xy - 4{y^2}\\
= {x^3}{y^2} - {x^2}y + 2xy - 2{x^2}{y^3} + 2x{y^2} - 4{y^2}\\
d)\left( {x - y} \right)\left( {{x^2} + xy + {y^2}} \right)\\
= {x^3} - {y^3}
\end{array}\)

Vote (0) Phản hồi (0) 2 năm trước

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Giúp mình với nhé!!! Thank các bạn ;-;

help e nhanh vs ạ plss đó .Lm đầy đủ ko lm tắt ạ

Alo ạ? Ai giúp mình với:^ mik đag cần gấp ಥ╭╮ಥ

với mọi n là số nguyên lẻ.chứng minh rằng:B=n³+3n+2412 chia hết cho 8

nhanh giúp mk nha, mk đang cần gấp

rút gọn biểu thức 2x^2+4y^2+5y^2-2x^2+12xy

1+2+3+...+x=78 làm hộ mình nha

nhanh giúp mk nha, mk đang cần gấp

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