tim tich cua hai don thuc
-2*x^2*y^2*z va -1/3*x^2*y^3
tim tich cua hai don thuc sau:
2/3*x^2*y*z va -3*x*y^2
Ta có: \(\dfrac{2}{3}x^2yz\cdot\left(-3xy^2\right)\)
\(=\left(-\dfrac{2}{3}\cdot3\right)\cdot\left(x^2\cdot x\right)\cdot\left(y\cdot y^2\right)\cdot z\)
\(=-2x^3y^3z\)
`(2/3x^2.y.z).(-3x.y^2)`
`=-3.(2/3).x^2.y.z.x.y^2`
`=-1.x^{2+1}.y^{2+1}.z`
`=-x^3y^3z`
NHan cac don thuc sau va tim bac va he so cua don thuc nhan duoc:
(\(\frac{1}{3}\)x\(^3\)y).(-xy)\(^2\)
NHan cac don thuc sau va tim bac va he so cua don thuc nhan duoc:
(\(\dfrac{1}{3}\)x\(^3\)y).(-xy)\(^2\)
\(\left(\dfrac{1}{3}x^3y\right)\left(-xy\right)^2=\left(\dfrac{1}{3}x^3y\right).x^2y^2=\dfrac{1}{3}x^5y^3\)
Bậc: 5
Hệ số: \(\dfrac{1}{3}\)
NHan cac don thuc sau va tim bac va he so cua don thuc nhan duoc:
(\(\frac{1}{3}\)x\(^3\)y).(-xy)\(^2\)
ta có (sau khi nhân) đơn thưc
-\(\frac{1}{3}\)x5y3
bậc là 5. hệ số -1/3
cho don thuc A=19/5 xy^2(x^3y)(-3x^13y^5)^0
a, thu gon don thuc A
b, tim he so va bac cua don thuc
c, tinh gia tri cua don thuc tai x=1, y=2
a: \(A=\dfrac{19}{5}xy^2\cdot x^3y=\dfrac{19}{5}x^4y^3\)
b: Hệ số là 19/5 và bậc là 7
c: Khi x=1 và y=2 thì \(A=\dfrac{19}{5}\cdot1^4\cdot2^3=\dfrac{19}{5}\cdot8=\dfrac{152}{5}\)
thu gon don thuc tim bac he so cua da thuc A=x^3 *(-5/4*x^2*y)*(2/5*x^3*y^4)
A=x^3*(-5/4x^2y)*(2/5x^3y^4)
A=(1*-5/4*2/5)*(x^3*x^2*x^3*y*y^4)
A=-1/2x^8y^5
bậc:13
hệ số:-1/2
bai 1: Cho cac don thuc A=-4/9x^3y va B= 3/8 x^5y^3. Tim cac cap gia tri (x;y)de A,B cung gia tri am
bai 2: viet don thuc B=64xy^12 duoi dang luy thua cua 1 don thuc voi so mu khac 1
bai 3: cho A=8x^5y^3; B=-3x^6y^3; C=-6x^7y^2. CM: Ax^2+Bx+C>0
Cho don thuc A=(-2xy)-4/5x^2y^3 a,Thu gon don thuc tren ,cho biet phan he so va phan bien ,tim bac cua don thuc b,Tinh gia trim cua don thuc tai x=1,y=-1
a, P=-3(x^3.x)(y^2.y^3)
=-3x^4y^5
b, Thay x=-1 , y=2 vào đơn thức P . Ta có :
P=-3.(-1)^4.2^5
P=3.1.32
P=96
Cho don thuc A=(-2xy)-4/5x^2y^3 a,Thu gon don thuc tren ,cho biet phan he so va phan bien ,tim bac cua don thuc b,Tinh gia trim cua don thuc tai x=1,y=-1