Bài 3:
a) \(xyx^3\left(-2xy\right)\left(-3y\right)\)
\(=x^4y\left(-2xy\right)\left(-3y\right)\)
\(=x^4y\cdot6xy^2\)
\(=6x^5y^6\)
Hệ số là 6
b) \(3x^3y^2\left(-a^2x\right)^3\left(-y\right)\)
\(=3x^3y^2\cdot\left(-a^6x^3\right)\cdot\left(-y\right)\)
\(=\left(3\cdot-a^6\cdot-1\right)\left(x^3\cdot x^3\right)\left(y^2\cdot y\right)\)
\(=3a^6x^6y^3\)
Hệ số là \(3a^6\)
c) \(-\dfrac{3}{2}y\cdot\left(-\dfrac{4}{3}x^3y\right)\)
\(=\left(-\dfrac{3}{2}\cdot-\dfrac{4}{3}\right)x^3\cdot\left(y\cdot y\right)\)
\(=2x^3y^2\)
Hệ số là 2
d) \(\left(-\dfrac{1}{3}xy^2z\right)\left(-\dfrac{3}{5}x^2y\right)\)
\(=\left(-\dfrac{1}{3}\cdot-\dfrac{3}{5}\right)\left(x\cdot x^2\right)\left(y^2\cdot y\right)z\)
\(=\dfrac{1}{5}x^3y^3z\)
Hệ số là \(\dfrac{1}{3}\)
1:
a: =6x^2+3x-6x^2+18x-x+3
=20x+3=-80+3=-77
b: =(x^2-4)(x+1-x)
=x^2-4
=10^2-4=96
