5:

=10x^3*1/2xy-2/5y*1/2xy+1/2z*1/2xy

=5x^3y-1/5xy^2+1/4xyz

6: =x^2y*4xy+x^2y*3y-5x*x^2y

=4x^3y^2+3x^2y^2-5x^3y

7: =-4/3xy*3x^2y+4/3xy*6xy-4/3xy*9x

=-4x^3y^2+8x^2y^2-12x^2y

`5)(-10x^3+2/5y-1/2z)(-1/2xy)`

`=5x^4 y-1/5xy^2+1/4xyz`

`6)x^2 y(4xy+3y-5x)`

`=4x^3 y^2+3x^2 y^2-5x^3 y`

`7)(-4/3xy)(3x^2 y-6xy+9x)`

`=-4x^3 y+8x^2 y^2-12x^2 y`

\(\left|x+\dfrac{1}{7}\right|-\dfrac{2}{3}=0\)

\(\Rightarrow\left|x+\dfrac{1}{7}\right|=0+\dfrac{2}{3}\\ \Rightarrow\left|x+\dfrac{1}{7}\right|=\dfrac{2}{3}\)

\(\Rightarrow\left[{}\begin{matrix}x+\dfrac{1}{7}=\dfrac{2}{3}\\x+\dfrac{1}{7}=-\dfrac{2}{3}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{2}{3}-\dfrac{1}{7}\\x=-\dfrac{2}{3}-\dfrac{1}{7}\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{11}{21}\\x=-\dfrac{17}{21}\end{matrix}\right.\)

em cảm ơn nhiều ạ

bài nào bạn?

Bài nào vậy bạn? Mik ko thấy

ΔMNP vuông

a: =>2x^3-2x^2+2x-x^2+x-1+3x^2-2x^3=2

=>3x-1=2

=>x=1

b: \(\Leftrightarrow\left(3x-6\right)\left(-4x+1\right)+4\left(3x^2+7x+2\right)=24\)

=>\(-12x^2+3x+24x-6+12x^2+28x+8=28\)

=>55x+2=28

=>55x=26

=>x=26/55

c: \(\Leftrightarrow\left(x^2+3x+2\right)\left(x+3\right)-x^3-8x^2-16x=6\)

=>\(x^3+3x^2+3x^2+9x+2x+6-x^3-8x^2-16x=6\)

=>-2x^2-5x=0

=>x=0 hoặc x=-5/2

d: =>x^3+2x^2+4x+x^2+2x+4-x^3-3x^2+8=0

=>6x+12=0

=>x=-2

Bài 2:

\(\dfrac{1}{2}:\dfrac{5}{4}=x:\dfrac{10}{3}\Leftrightarrow\dfrac{1}{2}.\dfrac{4}{5}=\dfrac{3}{10}x\Leftrightarrow\dfrac{3}{10}x=\dfrac{2}{5}\Leftrightarrow x=\dfrac{2}{5}:\dfrac{3}{10}=\dfrac{4}{3}\)

Bài 3:

Áp dụng t/c dtsbn:

\(\dfrac{x}{4}=\dfrac{y}{12}=\dfrac{x+y}{4+12}=\dfrac{48}{16}=3\)

\(\Rightarrow\left\{{}\begin{matrix}x=3.4=12\\y=3.12=36\end{matrix}\right.\)