a/ 3xy(x + y) – (x+y)(x^2 + y^2 + 2xy) + y^3 = 27 b/ (8x – 3)(3x + 2) – (4x + 7)(x + 4) = (2x + 1)(5x – 1) – 33 31/07/2021 Bởi Alice a/ 3xy(x + y) – (x+y)(x^2 + y^2 + 2xy) + y^3 = 27 b/ (8x – 3)(3x + 2) – (4x + 7)(x + 4) = (2x + 1)(5x – 1) – 33
a)3xy(x + y) – (x+y)(x^2 + y^2 + 2xy) + y^3 = 27 =3x²y+3xy²-x³+xy²+2x²y+x²y+y³+2xy²+y³=27 =2y³+6xy²+6x²y-x³ xin lỗi bạn câu b mình ko biết làm chúc bạn học tốt Bình luận
`a,3xy(x + y) – (x+y)(x^2 + y^2 + 2xy) + y^3 = 27` `3x²y+3xy²-x³+xy²+2x²y+x²y+y³+2xy²+y³=27` `2y³+6xy²+6x²y-x³` `b,(8x−3)(3x+2)−(4x+7)(x+4)+(2x+1)(1−5x)=−33` `⇔3x(8x−3)+2(8x−3)−[x(4x+7)+4(4x+7)]+(2x+1)−5x(2x+1)+33=0` `⇔24x^2−9x+16x−6−(4x^2+7x+16x+28)+2x+1−10x^2−5x+33=0` ⇔24x^2−9x+16x−6−4x^2−7x−16x−28+2x+1−10x^2−5x+33=0` `⇔10x^2−19x=0` `⇔x(10x−19)=0` `⇔`\(\left[ \begin{array}{l}x=0\\10x-19=0\end{array} \right.\) `⇔` \(\left[ \begin{array}{l}x=0\\x=\dfrac{19}{10}\end{array} \right.\) Xin hay nhất ! Bình luận
a)3xy(x + y) – (x+y)(x^2 + y^2 + 2xy) + y^3 = 27
=3x²y+3xy²-x³+xy²+2x²y+x²y+y³+2xy²+y³=27
=2y³+6xy²+6x²y-x³
xin lỗi bạn câu b mình ko biết làm chúc bạn học tốt
`a,3xy(x + y) – (x+y)(x^2 + y^2 + 2xy) + y^3 = 27`
`3x²y+3xy²-x³+xy²+2x²y+x²y+y³+2xy²+y³=27`
`2y³+6xy²+6x²y-x³`
`b,(8x−3)(3x+2)−(4x+7)(x+4)+(2x+1)(1−5x)=−33`
`⇔3x(8x−3)+2(8x−3)−[x(4x+7)+4(4x+7)]+(2x+1)−5x(2x+1)+33=0`
`⇔24x^2−9x+16x−6−(4x^2+7x+16x+28)+2x+1−10x^2−5x+33=0`
⇔24x^2−9x+16x−6−4x^2−7x−16x−28+2x+1−10x^2−5x+33=0`
`⇔10x^2−19x=0`
`⇔x(10x−19)=0`
`⇔`\(\left[ \begin{array}{l}x=0\\10x-19=0\end{array} \right.\)
`⇔` \(\left[ \begin{array}{l}x=0\\x=\dfrac{19}{10}\end{array} \right.\)
Xin hay nhất !