=xy^2z.(3-1+4)=xy^2z.6

=>6xy^2z

0,2:x=1,03+3,97

a: A=-2xy+xy+xy^2=-xy+xy^2

Bậc là 3

b: \(B=xy^2z+2xy^2z-3xy^2z+xy^2z-xyz=-xyz+xy^2z\)

Bậc là 4

c: \(C=4x^2y^3-x^2y^3+x^4+6x^4-2x^2=3x^2y^3+7x^4-2x^2\)

Bậc là 5

d: \(D=\dfrac{3}{4}xy^2-\dfrac{1}{2}xy^2+xy=\dfrac{1}{4}xy^2+xy\)

bậc là 3

e: \(E=2x^2-4x^2+3z^4-z^4-3y^3+2y^3\)

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

Bậc là 4

f: \(=3xy^2z+xy^2z+2xy^2z-4xyz=6xy^2z-4xyz\)

Bậc là 4

a: =xy(1/3+4-2)=7/3xy

b: =xy^2(-1+3/2+4/3)=(1/3+3/2)xy^2=11/6xy^2

c: =4x^2y^2+2/3x^2y^2-4/3x^2y=-4/3x^2y+14/3x^2y^2

d: =3x^2y^2z+4x^2y^2z-8x^2y^2z=-x^2y^2z

\(=\dfrac{5x^5y^4z}{\dfrac{1}{4}xy^2z}+\dfrac{\dfrac{1}{2}x^4y^2z^3}{\dfrac{1}{4}xy^2z}-\dfrac{2xy^3z^2}{\dfrac{1}{4}xy^2z}\)

=20x^4y^2+2x^3z^2-8yz

a) x²+y²-4x+4y+8=0

⇔ (x-2)²+(y+2)²=0

\(\Leftrightarrow\left\{{}\begin{matrix}x-2=0\\y+2=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=2\\y=-2\end{matrix}\right.\)

b)5x²-4xy+y²=0

⇔ x²+(2x-y)²=0

\(\Leftrightarrow\left\{{}\begin{matrix}x=0\\2x-y=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=0\\y=0\end{matrix}\right.\)

c)x²+2y²+z²-2xy-2y-4z+5=0

⇔ (x-y)²+(y-1)²+(z-2)²=0

\(\Leftrightarrow\left\{{}\begin{matrix}x-y=0\\y-1=0\\z-2=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=y=1\\z=2\end{matrix}\right.\)

b: Ta có: \(5x^2-4xy+y^2=0\)

\(\Leftrightarrow x^2-\dfrac{4}{5}xy+y^2=0\)

\(\Leftrightarrow x^2-2\cdot x\cdot\dfrac{2}{5}y+\dfrac{4}{25}y^2+\dfrac{21}{25}y^2=0\)

\(\Leftrightarrow\left(x-\dfrac{2}{5}y\right)^2+\dfrac{21}{25}y^2=0\)

Dấu '=' xảy ra khi \(\left\{{}\begin{matrix}x=0\\y=0\end{matrix}\right.\)

d)3x²+3y²+3xy-3x+3y+3=0

⇔ 6x²+6y²+6xy-6x+6y+6=0

⇔ 3(x+y)²+3(x-1)²+3(y+1)²=0

\(\Leftrightarrow\left\{{}\begin{matrix}x+y=0\\x-1=0\\y+1=0\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}x=1\\y=-1\end{matrix}\right.\)

a) \(x^2+5x^2+\left(-3x^2\right)=x^2+5x^2-3x^2=\left(1+5-3\right).x^2=3x^2\)

b) \(5xy^2+\frac{1}{2}xy^2+\frac{1}{4}xy^2+\left(-\frac{1}{2}\right)xy^2=5xy^2+\frac{1}{4}xy^2=\left(5+\frac{1}{4}\right)xy^2=\frac{21}{4}xy^2\)

c) \(3x^2y^2z^2+x^2y^2z^2=\left(3+1\right)x^2y^2z^2=4x^2y^2z^2\)

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a, \(x^2+5x^2+\left(-3x^2\right)=3x^2\)

b, \(5xy^2+\frac{1}{2}xy^2+\frac{1}{4}xy^2+\left(-\frac{1}{2}\right)xy^2=\frac{11}{2}xy^2+\left(-\frac{1}{4}\right)xy^2=\frac{21}{4}xy^2\)

c, \(3x^2y^2z^2+x^2y^2z^2=4x^2y^2z^2\)

\(3xy^2z+2x^2yz-4xy^2z-5x^2yz-2xyz=-xy^2z-3x^2yz-2xyz=-xyz\left(y+3x+2\right)\)

\(3xy^2z+2x^2yz-4xy^2z-5x^2yz-2xyz\)

\(=-2xyz+\left(2x^2yz-5x^2yz\right)+\left(3xy^2z-4xy^2z\right)\)

\(=-2xyz-3x^2yz-xy^2z\)

a: =-2x^2y^3z^2

Hệ số: -2

bậc: 7

b: =-1/3x^3y^3

hệ số: -1/3

bậc: 6

c: =-1/2x^6y^5

hệ số: -1/2

bậc: 11

d: =-2/3x^3y^4

hệ số: -2/3

bậc: 7

e: =3/4x^3y^4

hệ số:3/4

bậc: 7

A=2x³y⁴ ; hệ số là 2; bậc là 7
B=-1/4xy³z; hệ số là -1/4; bậc là 5
C=36x⁶y⁴z²; hệ số là 36; bậc là 12
D=2/15x⁵y³; hệ số là 2/15; bậc là 8