Answer:
18x^2 y^8
Step-by-step explanation:
2(-3xy^4)^2
We know that (ab)^x = a^x b^x
2 * (-3)^2 x^2 y^4^2
2 *9 x^2 y^4^2
We know that a^b^c = a^(b*c)
18 x^2 y^(4*2)