Bài 7:
a: \(B=\left(-\dfrac{2}{3}xy^2\right)\cdot\left(-\dfrac{1}{4}x^2y^3\right)=\left(-\dfrac{2}{3}\right)\cdot\left(-\dfrac{1}{4}\right)\cdot\left(x\cdot x^2\right)\cdot\left(y^2\cdot y^3\right)\)
\(=\dfrac{1}{6}x^3y^5\)
Bậc là 3+5=8
Hệ số là 1/6
Bài 1:
a: \(A=2x^2y^2-3xy^2-2x^2y^2+xy^2+xy\)
\(=\left(2x^2y^2-2x^2y^2\right)+\left(-3xy^2+xy^2\right)+xy\)
\(=-2xy^2+xy\)
b: \(B=2xy-xy^2+x^2y-5xy+xy^2\)
\(=\left(2xy-5xy\right)+\left(-xy^2+xy^2\right)+x^2y=x^2y-3xy\)
c: \(C=x^3y^2-2x^2y^2-4xy^2-x^3y^2+3x^2y^2\)
\(=\left(x^3y^2-x^3y^2\right)+\left(3x^2y^2-2x^2y^2\right)-4xy^2\)
\(=x^2y^2-4xy^2\)
d: \(D=-3x^2y^2z-xy^2z+2x^2y^2z+4xy^2z\)
\(=\left(-3x^2y^2z+2x^2y^2z\right)+\left(-xy^2z+4xy^2z\right)\)
\(=-x^2y^2z+3xy^2z\)
