a/ \(\left(-2x^3\right)3x^4y\)
\(=\left(-2.3\right)\left(x^3.x^4\right)y\)
\(=\left(-6\right)x^7y\)
Bậc là 8
b/ \(\left(-\dfrac{1}{3}\right)\left(-3x^2y^2z\right)^2\)
\(=\left(-\dfrac{1}{3}\right)\left(9x^4y^4z^2\right)\)
\(=\left(-3\right)x^4y^4z^2\)
Bậc là 10
c/ \(\left(-\dfrac{1}{9}\right).9x^2yz\)
\(=\left(-\dfrac{1}{9}.9\right)x^2yz\)
\(=-x^2yz\)
Bậc là 4